# Singema — Full content > Singema is a professional factory specializing in wood fired hot tub heating coils & outdoor spa wood boiler systems, reliable, corrosion-resistant stainless steel heating solutions for residential & commercial hot tubs. --- ## How to Plan a Safe and Efficient DIY Wood-Fired Hot Tub Setup URL: https://www.singema.com/how-to-plan-a-safe-and-efficient-diy-wood-fired-hot-tub-setup.html A wood-fired hot tub is one of the simplest ways to create an off-grid spa experience at home, at a cabin, or at a campsite. With the right heater coil, safe layout, and a few practical accessories, a basic tub or stock tank can become a relaxing outdoor soaking station without relying on electricity. This guide explains how to plan a safe, efficient DIY wood-fired hot tub setup using Singema resources and support guides. If you are still comparing options, start with the main Wood Fired Hot Tub Systems, Heating Coils & Supporting Accessories page to see available coil kits and accessories. 1. Choose the right tub and location first Before choosing a coil, decide where the hot tub will sit and what type of vessel you will use. Common DIY options include stock tanks, wooden tubs, insulated plastic tubs, or custom-built soaking containers. The best location is flat, stable, well-drained, and positioned away from flammable walls, fences, dry leaves, and overhanging branches. For a full build overview, read Singema’s step-by-step page: How to Build a Wood-Fired Hot Tub with a Heater Coil Kit. It is especially useful if you are planning the project from the ground up. 2. Match the heater coil to your soaking style The heater coil is the heart of a wood-fired hot tub system. Water circulates through the stainless steel coil, absorbs heat from the fire, and returns warmer water to the tub. This natural circulation process is often called thermosiphon circulation, and it works best when the coil, hose connections, and tub water level are arranged correctly. For shoppers comparing different designs, the Singema Wood Fired Hot Tub Coil Kits - All Models A1 - F4 page is a helpful starting point. If you want a more advanced all-weather setup, you can also review models such as the Model E4 with Fireguard, Stop & Freeze Drain Valve or the Model F3 with Fireguard and BBQ Grille. 3. Plan safe water circulation Good circulation helps the system heat evenly and reduces hot spots. In most DIY setups, the lower connection draws cooler water from the tub into the coil, while the upper connection returns heated water back into the tub. Keep hoses as short and direct as practical, avoid sharp bends, and make sure the connections are secure before lighting the fire. If your tub has a curved, corrugated, or uneven wall, take extra care with the fittings. Singema’s guide How to install connector fitting on corrugated tub side? explains how to approach a leak-resistant installation. 4. Follow fire and soaking safety rules Wood-fired bathing is relaxing, but it still involves open flame, hot metal, and hot water. Place the heater coil on a stable, fire-safe surface, keep children and pets away from the fire area, and never leave the fire unattended. Always stir the water and test the temperature before entering the tub. For more detailed precautions, visit Singema’s Safety Guidelines. You can also review Tips to use for practical operating advice before your first soak. 5. Add accessories that make the setup easier Small accessories can improve comfort and usability. A fireguard can help shield the flame from wind, a drain valve can simplify cold-weather maintenance, and a suitable hose kit can make setup cleaner and more dependable. Some Singema kits also support grilling accessories, turning the hot tub heater area into a more complete outdoor relaxation setup. If you are heating a larger tub, two tubs, or a special container, compare standard models with custom options. The Tailor-made Wood Fired Hot Tub Coil Kit page is useful for personalized configurations, while the Dual-coil kit for heating double tubs may fit multi-tub projects. 6. Prepare a simple heating routine A consistent routine makes wood-fired soaking more enjoyable. Fill the tub above the circulation fittings, confirm that water can move through the system, start with a modest fire, and increase fuel gradually. Stir the tub regularly so the water temperature stays even from top to bottom. Heating time depends on tub volume, starting water temperature, outdoor weather, wind exposure, and the size of the fire. For more guidance on operating a coil safely, read How to Use a Wood-Fired Hot Tub with a Coil Heater Safely. Final thoughts A DIY wood-fired hot tub setup does not need to be complicated. Start with a safe location, choose a heater coil that matches your tub size and soaking goals, install fittings carefully, and follow safe fire-handling habits every time you heat the water. If you still have questions, visit the FAQ page or contact Singema through Contact Us for help choosing a suitable coil kit for your project. --- ## How Does a Wood-Fired Hot Tub Coil Work? Thermosyphon Explained URL: https://www.singema.com/how-does-a-wood-fired-hot-tub-coil-work.html A wood-fired hot tub coil is a stainless steel heat exchanger that warms your tub water using nothing but fire and gravity. No electricity, no pump, no gas line. If you have ever wondered how a coil of metal tubing can heat hundreds of gallons of water to soaking temperature, the answer comes down to a natural process called thermosyphon. This guide breaks down exactly how a wood-fired hot tub coil works, step by step, so you understand the physics before you buy or build. TL;DR: A wood-fired hot tub coil works through thermosyphon. Fire heats the water inside the stainless steel coil, the hot water naturally rises and flows back into the tub, and cooler water from the bottom of the tub is drawn into the coil to replace it. This creates a continuous, pump-free circulation cycle powered only by heat and gravity. What Is a Wood-Fired Hot Tub Coil? A wood-fired hot tub coil is a spiraled or looped tube, typically made from food-grade 304 stainless steel, that sits beside or below your tub in a fire pit or wood holder. One end of the coil connects to the lower part of the tub (the cold water intake) and the other end connects to the upper part (the hot water outlet). A fire is built inside or beneath the coil, and the metal tubing absorbs that heat and transfers it directly into the water flowing through it. The coil functions as a heat exchanger. The fire never touches your tub water directly. Instead, the stainless steel walls of the coil conduct heat from the flames into the water passing through the tubing. Because stainless steel is an excellent heat conductor and resists corrosion at high temperatures, it is the ideal material for this job. Singema's coil kits include the heating coil itself along with fire-resistant hoses, tub fittings, a wood holder, an ash collector, and optional accessories like a BBQ grille and rain deflector. You can browse all coil kit models here. The Core Principle: How Thermosyphon Works The entire heating process relies on thermosyphon, also called natural convection or gravity circulation. Here is the physics in plain language: - Fire heats the water inside the coil. As flames surround the stainless steel tubing, the water inside the coil absorbs heat through the metal walls. - Hot water rises. When water heats up, it expands and becomes less dense. This makes it lighter than the cooler water in the tub, so it naturally rises and flows out the top of the coil. - Hot water enters the tub. The heated water travels through the outlet hose and flows into the upper part of your tub. - Cold water is drawn in. As hot water leaves the coil, it creates a pressure difference that pulls cooler, denser water from the bottom of the tub into the coil's inlet. This cooler water then gets heated, rises, and the cycle repeats. This creates a steady, silent circulation loop. Hot water continuously flows into the tub while cold water continuously flows into the coil. No pump is needed because the temperature difference itself drives the flow. The greater the temperature difference between the fire and the tub water, the faster the circulation. You can learn more about the underlying physics on our dedicated page explaining the principle of thermosyphon. Step-by-Step: How a Wood-Fired Hot Tub Coil Heats Your Tub 1. You Fill the Tub and Connect the Coil Fill your tub with water from a garden hose or other source. The coil kit connects to the tub using two fire-resistant hoses. The lower hose draws cold water from near the bottom of the tub into the coil inlet. The upper hose returns heated water from the coil outlet into the upper portion of the tub. The system must be primed, meaning both hoses and the coil are filled with water before you light the fire, so the siphon can start. 2. You Build a Fire Inside the Coil Place kindling and firewood inside the center of the coil, in the wood holder or fire pit area. Light the fire just as you would a campfire. The flames surround the coiled tubing, and the stainless steel walls begin absorbing heat immediately. 3. The Water Inside the Coil Heats Up Within minutes, the water inside the coil reaches temperatures well above the tub water. The metal tubing transfers heat efficiently because of its large surface area. A coil with more loops or wider tubing exposes more water to heat at once, which is why coil design directly affects heating speed. You can read more about improving coil heater performance through surface area. 4. Thermosyphon Circulation Begins Once the water inside the coil is hotter than the water in the tub, the density difference kicks in. Hot water rises out of the coil and into the tub. Cold water from the tub floor flows in to replace it. The circulation starts slowly and speeds up as the temperature gap widens. 5. The Tub Reaches Soaking Temperature Depending on your tub size, insulation, fire intensity, and outside temperature, the water typically reaches 38 to 40 degrees Celsius (100 to 104 degrees Fahrenheit) within 1.5 to 3 hours. Larger tubs take longer. You can speed things up by using dry hardwood, keeping the fire stoked, and minimizing hose length to reduce heat loss between the coil and the tub. Our tips for maximizing coil efficiency cover this in detail. 6. You Maintain the Temperature Once the tub is hot enough, you reduce the fire to a maintenance level. Add small pieces of wood periodically to hold the temperature where you want it. A stop valve on the hose lets you control or shut off circulation if the water gets too hot, which is a feature included on most Singema coil kit models from the C series and above. What Makes a Wood-Fired Coil Efficient? Several design factors determine how fast and how well a coil heats your tub: - Surface area: More loops of tubing mean more contact between fire and water. Coils with 8 to 12 circles are common, and wider tubing (such as 32mm instead of 25mm) increases water volume in the heat zone. - Material thickness and grade: 304 food-grade stainless steel balances heat conductivity with corrosion resistance. Thinner walls transfer heat faster but may be less durable over years of use. - Coil placement: The coil should sit so the fire surrounds as much of the tubing as possible. A fire pit or wood holder that concentrates heat against the coil improves efficiency. - Hose length and angle: Shorter, straighter hoses between the coil and tub reduce heat loss and flow resistance. Hoses should slope upward from the tub to the coil outlet to help the natural flow. - Wind protection: A fireguard or wind shield around the coil prevents heat from being blown away and keeps the fire burning steadily even in breezy conditions. How a Coil Compares to Other Wood-Fired Heating Methods Not all wood-fired hot tubs use a coil. Here is how the coil approach compares to the main alternative: Feature Coil Heater (External) Internal Wood Stove Placement Outside the tub, connected by hoses Mounted inside the tub wall Electricity needed None (thermosyphon) None (convection) Tub space used None, coil is external Takes up interior space Portability High, coil kit is movable Low, stove is fixed Works with any tub Yes, including stock tanks and barrels Requires a compatible tub with stove port BBQ cooking Yes, grill sits over the fire Usually no The coil approach is more versatile because it works with almost any container that holds water. You can convert a stock tank, a wooden barrel, a fiberglass tub, or even a galvanized trough into a wood-fired hot tub. If you are starting from scratch, our guide on building a wood-fired hot tub with a coil kit walks you through the full process. Frequently Asked Questions Does a wood-fired hot tub coil need a pump? No. The coil relies entirely on thermosyphon, which is natural circulation driven by the temperature difference between the heated water in the coil and the cooler water in the tub. Hot water rises and cold water sinks, creating a continuous flow without any mechanical pump or electricity. How does a wood-fired hot tub circulate water? Water circulates through a simple loop. Cold water from the bottom of the tub flows through the lower hose into the coil. The fire heats that water inside the coil. The heated water, now less dense, rises and flows out through the upper hose back into the tub. This cycle repeats continuously as long as the fire is burning. How long does it take to heat a tub with a coil? Heating time depends on tub volume, insulation, fire intensity, and outside temperature. A typical 500-liter uninsulated tub reaches 40 degrees Celsius in about 1.5 hours. A 1,000-liter insulated tub takes roughly the same. Larger tubs of 1,500 to 2,000 liters may take 2.5 to 3 hours. Using dry hardwood and keeping the fire stoked reduces heating time. Can I use a wood-fired hot tub coil in winter? Yes. The coil works in cold weather, though heating times will be longer because more heat is lost to the surrounding air. Models with a freeze drain valve, such as the Singema E4, C4, and F-series kits, let you drain the coil and hoses after use to prevent freezing and cracking. A rain deflector also helps protect the fire in snow or rain. What are the disadvantages of a wood-fired hot tub coil? The main drawbacks are heating time (1.5 to 3 hours versus 20 to 30 minutes for electric heaters), the need to manually tend the fire, and the requirement for a supply of dry firewood. Temperature control is less precise than an electric thermostat. However, the tradeoff is zero operating cost, complete off-grid capability, and a more natural soaking experience. For a balanced look, see our post on whether wood-fired hot tubs are worth it. Is a wood-fired hot tub coil safe? Yes, when used correctly. The coil and its hoses can get very hot during operation, so avoid touching the metal tubing or hoses while the fire is burning. Always place the coil on a non-flammable surface or use the included ground support and ash pan. Keep children and pets away from the fire area. Our safety guidelines and safe usage guide cover everything you need to know. Ready to Heat Your Tub With Fire? A wood-fired hot tub coil is one of the simplest, most reliable off-grid heating methods available. The thermosyphon principle means no moving parts, no electricity, and no ongoing fuel costs beyond firewood. Whether you are heating a stock tank, a cedar barrel, or a custom DIY tub, a stainless steel coil kit gives you hot water anywhere you can build a fire. Explore Singema's full range of wood-fired hot tub coil kits, from the basic Model A1 starter kit to the all-weather Model F4 with dual BBQ, freeze protection, and rain deflector. Every kit is built from food-grade 304 stainless steel and ships worldwide. Not sure which model fits your tub? Read our guide to choosing the right wood-fired hot tub heater coil or contact us for a personalized recommendation. --- ## Off-Grid Luxury: Singema Model D2 Wood-Fired Hot Tub Coil Review – Heat & Grill Without Power URL: https://www.singema.com/off-grid-luxury-singema-model-d2-wood-fired-hot-tub-coil-review-heat-grill-without-power.html If you dream of steamy backyard soaks, wilderness glamping baths, or off-grid homestead relaxation—but hate relying on noisy electric heaters, costly propane tanks, or bulky built-in wood stoves—this deep dive is for you. I’ve spent weeks testing the Singema Model D2 wood-fired hot tub coil kit, a compact 304 stainless steel heat exchanger that doubles as a portable BBQ grill. After hauling it to my cabin, beach camping trips, and backyard barrel tub setup, I’m breaking down exactly who this tool is for, how easy it is to install, and why it beats every single competitor coil I’ve tried before. No hard sales fluff—just honest hands-on testing, assembly walkthroughs, and real-world performance breakdowns for outdoor, off-grid lovers. The Big Pain Point Most DIY Hot Tub Owners Face Anyone who’s built a homemade stock tank or barrel hot tub knows the biggest frustration: heating options are limited and flawed. Electric heaters rack up massive utility bills and require grid power. Propane setups demand constant tank refills and carry fire risks near plastic tubs. Cheap imported wood coils rust within one winter, crack in freezing weather, or take hours to warm water. Worse, separate wood burners and portable grills double your gear load for camping trips. That’s where the Singema Model D2 solves multiple pain points in one all-in-one kit. It’s 100% off-grid, built from food-grade stainless steel to resist rust and freeze damage, combines water heating and outdoor grilling into a single lightweight unit, and assembles in three minutes flat with zero tools. I immediately noticed the difference when unboxing—this isn’t a thin, flimsy metal coil; every piece feels heavy-duty and engineered for year-round outdoor abuse. Unboxing & 3-Minute Tool-Free Assembly Walkthrough I’ll admit I dreaded complicated DIY assembly before opening the package, but the Model D2 design prioritizes beginner-friendliness above all else. The entire setup splits into two simple steps, no drills, wrenches, or specialty tools required. First, attach the three stainless steel ground support legs to the coil base frame. The pieces slot together with tight friction fits—no loose screws to lose mid-camping trip. Slide the included ash collector tray directly underneath the spiral coil to catch hot embers and ash, cutting down patio and lawn mess drastically. That’s the full heater unit assembled. Next, connect the coil to your wooden tub, plastic barrel, or livestock stock tank. You only need to drill two matching 25mm holes aligned with the coil’s outlet tubes. Slide the included rubber tub fittings through the openings, fasten the silicone hoses with stainless steel clamps, and you’re ready to fill your tub and light a fire. A quick pro tip from my testing: position the upper tub hole fully below the water line to avoid air bubbles slowing heat circulation. Disassembly is just as fast—30 seconds to unclamp hoses and separate the frame legs for compact storage in the optional matching carry bag. Standout Dual Functionality: Heat Tub Water + Cook BBQ Simultaneously My favorite feature after weeks of testing is the integrated built-in BBQ grille layered over the 8-circle spiral heat exchanger. Most wood coils only heat water and waste excess fire heat; the D2 repurposes that high-temperature flame for outdoor cooking without extra fuel. On weekend backyard nights, I stoked small logs inside the coil’s fire holder to warm my barrel tub while grilling vegetables, steaks, and seafood right above the flame. For remote camping trips without kitchen gear, I even set a small metal kettle on the grate to boil drinking water or brew coffee. The ash tray contains stray embers, so I never worried about burning grass or deck planks while cooking and soaking at the same time. The 8-spiral coil design maximizes surface contact with fire, cutting water heating time far below cheaper single-loop coils. The 25mm thick stainless tubing holds heat efficiently, and the food-grade material means zero toxic chemical leaching into bathwater—critical for anyone with sensitive skin or families using the tub regularly. Weather Resistance & Off-Grid Year-Round Reliability Many cheap wood coil kits fail spectacularly through winter freezes or rainy summer weather, but Singema’s material choice eliminates those headaches. The entire coil and frame use 304 food-grade stainless steel, fully rust-proof through rain, snow, and coastal salt air. The silicone connecting hoses withstand extreme temperatures from -200°C up to 200°C, so they won’t crack in frost or melt over hot fire. During a recent cold weekend with overnight freezing temperatures, I forgot to drain water from the coil overnight. When I returned the next morning, ice filled the tubing—but the thick metal held firm with no splits or bursts. While draining excess water after each use still extends lifespan, this freeze-resistant build removes the fear of accidental winter damage common with thinner metal alternatives. This all-weather durability makes the Model D2 perfect for permanent backyard setups, seasonal lake cabins, and remote off-grid homesteads without covered storage space. It ships fully disassembled with free worldwide shipping, and replacement custom-length hoses are available direct from the manufacturer if your tub sits further from the heater base. Who Is the Singema Model D2 Coil Actually For? After testing across multiple environments, I’ve broken down the exact audiences who will get the most value from this kit: - Backyard DIY barrel/stock tank hot tub hobbyists tired of expensive electric heating bills - Glamping and wilderness campers seeking lightweight multi-purpose outdoor gear (heater + grill combined) - Off-grid homesteaders and rural property owners without consistent grid electricity or propane access - Cabin and lake house owners looking for low-maintenance seasonal hot tub heating - Small-scale farmers needing a safe stainless steel solution to warm livestock water tanks in cold months If you live in an urban apartment with no outdoor yard space, this unit isn’t for you—it requires open-air ventilation and can only be used outside, per safety guidelines. But every outdoor-focused user category above will cut gear costs and storage space drastically with this all-in-one coil kit. Final Verdict & Quick Pro Maintenance Tips After hundreds of hours of real-world use, the Singema Model D2 stands out as the most well-rounded wood-fired hot tub coil kit I’ve reviewed this year. It solves core DIY heater pain points: flimsy construction, single-function design, complicated assembly, and poor cold-weather durability, all wrapped in a portable, budget-friendly package with full included accessories. A few simple maintenance habits to extend your coil’s lifespan: - Flush the spiral tubing with clean water after every use to remove mineral buildup - Store in the included fabric bag during long stretches of non-use - Empty standing water from the coil before extended freezing weather, when possible - Keep the ash collector tray emptied regularly to maintain steady heat flow Whether you’re planning summer beach camping soaks, quiet winter cabin baths, or daily backyard off-grid relaxation, this coil eliminates the hassle of separate heating and cooking gear while delivering consistent, chemical-free hot water for your DIY tub setup. For anyone prioritizing portability, dual functionality, and long-term weatherproof build quality, the Singema Model D2 is easily the top wood coil investment of 2026 for outdoor DIY enthusiasts. --- ## Wood Fired Hot Tub Coil Kits: Turn Any Tub Into an Off-Grid Spa in Minutes URL: https://www.singema.com/wood-fired-hot-tub-coil-kits-turn-any-tub-into-an-off-grid-spa-in-minutes.html Imagine soaking in warm, bubbly water under the stars—no power cords, no gas bills, just the crackle of fire and the scent of wood smoke. For off-grid enthusiasts, campers, and backyard adventurers, this dream is now achievable with wood fired hot tub coil kits from Singema. These innovative systems transform ordinary tubs (plastic, metal, cedar—you name it) into self-sustaining spas in minutes, solving the biggest pain points of traditional hot tubs: high energy costs, complex installations, and reliance on utilities. Wood Fired Hot Tub Coil Kits: Turn Any Tub Into an Off-Grid Spa in Minutes Why Off-Grid Enthusiasts Are Obsessed With Wood Fired Coil Kits Off-grid living shouldn’t mean sacrificing comfort. Singema’s wood fired coil kits address the top concerns users voice on forums like Reddit, Facebook Groups, and camping blogs: - “How do I heat a hot tub without electricity?” - “Will it work in freezing winters?” - “Is installation complicated for DIY beginners?” - “Can I use it while camping or in remote cabins?” The answer to all? Yes—with zero compromises. Key Benefits That Stand Out - No Electricity or Gas Required: Rely solely on firewood (local, affordable, and eco-friendly) to heat your tub. Perfect for blackouts, remote properties, or anyone wanting to reduce their carbon footprint . - Fast Heating & Efficient Performance: The stainless steel coil design transfers heat quickly—warm your tub in hours, not days. Even in cold climates, the freeze-protection drain valve (included in models like A4, B4, and F4) prevents damage . - 25+ Customizable Models: From the basic A1 (ideal for DIY beginners) to the advanced F4 (with wind guards, BBQ grills, and full hose kits), there’s a kit for every budget and use case. The Model D3 (Upper Popular) is a fan favorite for its balance of features and value. - 20+ Year Durability: Unlike competitors’ welded pipes (prone to leaks and corrosion), Singema uses seamless stainless steel pipes—no weak points, no rust, and decades of reliable use . How to Install Your Coil Kit in 4 Simple Steps (No DIY Experience Needed) Users often worry about complex installations, but Singema’s kits are designed for hassle-free setup. Here’s how easy it is: - Choose a Level Spot to put tub and drill hole on side: Place your tub on gravel, concrete, or a sturdy base (follow safety guidelines to keep the fire source away from flammable materials) . - Connect the Coil: Attach the stainless steel coil to your tub using the included heat-resistant silicone hoses and clamps. No special tools required—everything you need is in the box. - Tighten all clamps to assure no leakage. - Light the Fire: Add wood to the fire holder (included in C, D, E, and F series) and let nature do the rest. Stir the water occasionally for even heating, and use the stop valve to control flow . DIY installation takes 20 minutes or less—even for first-timers! Social Proof: What Real Users Are Saying Don’t just take our word for it—here’s what customers from the US, Canada, and Europe are sharing: “We installed the Model D3 at our cabin in Vermont, and it’s been a game-changer. Heats our 500-gallon tub in 3 hours, even when it’s 20°F outside. The BBQ grill add-on lets us cook while we wait—perfect for weekend getaways!” — David L., Vermont (Order #9665) “As a full-time RVer, I needed a portable heating solution. The Model A2 is lightweight, easy to store, and works with my plastic tub. No more paying for campground hookups—just gather firewood and relax!” — Sarah D., Colorado (Order #8870) “I was skeptical about durability, but after 3 winters in Canada, my Model F4 is still going strong. The wind guard keeps the fire burning even in blizzards, and the seamless pipe hasn’t shown a hint of rust. Worth every penny!” — Brent B., Ontario (Order #9650) Wood Fired Coil Kits vs. Other “Water-Saving” Solutions: A Clear Winner While products like dual-flush toilets focus on reducing water usage, Singema’s coil kits redefine sustainability by eliminating energy waste. Here’s how they compare: Solution Core Benefit Energy Use Long-Term Value Singema Wood Fired Coil Kit Off-grid heating, no utilities Zero (firewood only) 20+ years of use; low maintenance Electric Hot Tub Heater Convenient, consistent heat High (costs $50+/month to run) 5-8 year lifespan; prone to breakdowns Singema’s kit offers unique value: it doesn’t just save resources—it creates a sustainable lifestyle upgrade. Which Model Should You Choose? Not sure which kit fits your needs? Here’s a quick guide: - Camping/Portable Use: Model A2 (starter kit) or B1 (with BBQ grill) - Backyard Luxury: Model D3 (popular upper model) or F3 (with wind guard and bake function) - Extreme Climates: Model E4 or F4 (freeze protection + wind/smoke guards) For a fully personalized setup, check out the Tailor-made Wood Fired Hot Tub Coil Kit—customize components like coil length, hose materials, and add-ons. Final Thoughts: Your Off-Grid Spa Awaits Singema’s wood fired hot tub coil kits prove that off-grid living can be luxurious, eco-friendly, and affordable. Whether you’re upgrading your backyard, outfitting a cabin, or enhancing your camping trips, these kits turn any tub into a year-round retreat. Ready to transform your outdoor space? Explore all models here: Wood Fired Hot Tub Coil Kits – All Models Free shipping to the US, Canada, EU, Australia, and Japan—order today and start soaking under the stars in days! --- ## How to install connector fitting on corrugated tub side? (Leak-Proof Guide) URL: https://www.singema.com/how-to-install-connector-fitting-on-corrugated-tub-side-leak-proof-guide.html Installing a connector fitting on a corrugated tub side often leads to leaks—standard rubber gaskets on fittings can't seal the uneven, ridged surface effectively. Singema's solution? Strategic use of Teflon (PTFE) tape and inside-out installation with a purpose-built barrel drum fitting. This step-by-step guide simplifies the process for a leak-proof result. What You'll Need - Compatible connector fitting (match tub material: plastic/metal) - High-quality PTFE (Teflon) tape (food-grade for water contact) - Drill with hole saw (matching fitting diameter) - Fine-grit sandpaper (240-400 grit) - Clean cloth, adjustable wrench - Silicone sealant (optional, for extra protection) - Measuring tape, marker, safety goggles, gloves Step 1: Prep the Installation Spot Empty the tub and place it on a stable surface. Measure and mark the desired fitting location—avoid seams or sharp corrugation peaks. Wear safety gear, then drill slowly with a hole saw to create the hole; prevent cracking by applying gentle pressure. Use sandpaper to smooth hole edges (inside and out) to remove burrs, then wipe clean with a cloth to eliminate dust. Step 2: Wrap Fitting with Teflon Tape This is the leak-prevention key. Unlike typical thread-only wrapping, Singema recommends covering the flange and shaft: - Locate the fitting's flange (flat contact surface) and cylindrical shaft. - According to the space between fitting and hole edge, wrap 8-10 or more overlapping layers of Teflon tape around the shaft (from flange base outward) and the flange's outer edge. Wrap tightly but don't tear the tape—this builds a compressible barrier for corrugated gaps. - Add 2-3 layers to the fitting's threads (if applicable) for extra pipe/hose connection security. Step 3: Install Fitting Inside-Out Inserting from the tub's interior keeps the tape pressed against the corrugated surface—critical for sealing: - Push the taped fitting through the hole from inside the tub until the flange sits flush against the inner wall. - From outside, attach washers and locknut (included with the tub fitting). Tighten snugly with a wrench—avoid over-tightening, which can crack the tub or damage the seal. - Secure any hoses/pipes to connect tub fitting and wood fired heater coil. Step 4: Seal and Test for Leaks Optional step: apply a thin silicone bead around the flange (inside the tub) and locknut (outside) for maximum protection,. Smooth with a tool for even coverage, then let dry 24 hours (per sealant instructions). Fill the tub with water and let sit 30-60 minutes. Inspect for drips—if leaks occur, gently tighten the locknut or add more tape and sealant. Pro Tips to Avoid Mistakes - Never skip sanding: Rough edges puncture tape/gaskets. - Don't skimp on tape: 8-10 layers or more are needed to fill corrugated gaps. - Inside-out is non-negotiable: Outside installation pushes gaskets away from the surface. - Match fitting to hole size: Ill-fitting parts guarantee leaks. - Go easy on tightening: Corrugated tubs are flexible—over-tightening warps or cracks them. That`s all. Singema's method eliminates the frustration of corrugated tub leaks when installing tub fittings. By using much Teflon tape generously and installing from the inside out, you'll achieve a reliable, long-lasting fitting that works for residential or camping hot tubs—no more wasted time mopping up drips! For more details about choose heater coil to connect your tub, please find this article "How to Choose the Right Wood Fired Hot Tub Heater Coil" --- ## How to Turn Your Backyard into Your Personal Wellness Retreat URL: https://www.singema.com/how-to-turn-your-backyard-into-your-personal-wellness-retreat.html In our fast-paced, always-connected world, finding time for genuine relaxation can feel like a luxury. The idea of a wellness retreat is appealing—a dedicated space to unwind, recharge, and reconnect with yourself. But what if you didn't have to book an expensive trip or travel for hours to find that peace? The answer is closer than you think. Your own backyard has the potential to be transformed into a serene sanctuary, a personal wellness retreat designed for your ultimate relaxation. Here's how to create your own oasis of calm. 1. Define Your Zones: The Art of Intentional Space A great retreat has areas dedicated to different activities. Start by mapping out your yard. The Meditation Nook: Identify a quiet corner, perhaps under a tree or beside a fence. A simple weather-resistant cushion, a small water feature for soothing sounds, a desktop micro fireplace for gentle flickering warmth, and some wind chimes are all you need to create a perfect spot for mindfulness and deep breathing. The Yoga Deck: A level, stable surface is key. This could be a dedicated wooden deck, a paved patio, or even a durable outdoor rug on the grass. Keep a basket nearby with a yoga mat, blocks, and a blanket for stretching and grounding exercises as the sun rises or sets. The Social Fire Pit: Wellness is also about connection. A fire pit serves as a natural gathering point. Arrange comfortable seating around it for evening conversations, stargazing, or simply getting lost in the flickering flames. For a portable option, a folding portable wood-burning stove can provide the same warmth for smaller patios or camping trips. 2. Engage All Your Senses A true retreat isn't just about what you see; it's a full sensory experience. Sight: Use soft, warm lighting. Solar-powered fairy lights in trees, lanterns with flickering LED candles, and discreet path lights can make the space feel magical after dark. Sound: Mask neighborhood noise with the gentle sounds of nature. A small tabletop fountain, a bird feeder to attract chirping friends, or a playlist of ambient nature sounds can work wonders. Smell: Plant a "sensory garden" with fragrant herbs like lavender, jasmine, and mint. The natural aromatherapy will calm your nerves every time you step outside. 3. The Ultimate Hydrotherapy Experience No wellness retreat is complete without a element of water for relaxation and muscle relief. While a standard hot tub is great, there's a growing trend that combines rustic charm with deep, satisfying heat: the wood-fired hot tub. The beauty of a wood-fired hot tub lies in its simplicity and power. The heart of the system is the wood fired hot tub coil, a brilliantly efficient heating element. Instead of a complex electric system, the coil is placed directly in a compact, insulated firebox. As the fire burns, it heats the water circulating through the wood fired hot tub coil, transferring intense heat directly into the tub. This method heats the water surprisingly quickly, providing a steaking, soothing soak that feels deeply connected to the elements. There's something profoundly peaceful about heating your own water, listening to the crackle of the fire, and sinking into the warmth under a canopy of stars. For families, a multi-person portable wood-fired hot tub offers the same experience with room for everyone. 4. Cultivate a Green Sanctuary Surround yourself with life. Use container gardens, raised beds, or in-ground planting to create a lush, green environment. Growing your own vegetables or herbs adds a rewarding, mindful activity to your routine. The act of tending to plants is a known stress-reliever, making your retreat an active part of your wellness practice. 5. Establish Digital-Free Boundaries The most important rule for your backyard retreat: make it a phone-free zone (or at least, put it on silent and stow it away in a basket). This space is for disconnecting from digital noise so you can reconnect with yourself, your thoughts, and the people you share it with. Your Retreat Awaits You don't need a sprawling estate to create a personal haven. With a little intention and creativity, you can carve out a space that serves your need for peace and restoration. From the simple act of breathing in fragrant air to the deep, muscle-melting warmth provided by a wood fired hot tub coil, your backyard can become the most accessible and rewarding destination on your wellness journey. So step outside, take a deep breath, and start designing your escape. --- ## How to Choose a Wood Fired Hot Tub Heater Coil URL: https://www.singema.com/how-to-choose-the-right-wood-fired-hot-tub-heater-coil-discover-the-affordable-and-eco-friendly-benefits-for-your-backyard-oasis.html Choosing the right wood fired hot tub heater coil is the single most important decision you will make when building or upgrading an off-grid soaking tub. The coil is what transfers heat from your fire into the water, and the right size, material, and configuration determine how fast your tub heats, how long the coil lasts, and how much you spend. This guide walks through everything you need to know: how heater coils work, what to look for when buying, and which Singema coil kit fits your tub. See Which Singema Coil Kit Fits Your Tub A great coil is a masterpiece of simple, effective physics. Singema's kits are precisely designed to maximize surface area and create optimal water flow. Singema's genius is in the details—the robust, marine-grade stainless steel construction resists corrosion and scaling, while the meticulous welding ensures durability and leak-free performance season after season.Choose one model to fit for your tub: What Is a Wood Fired Hot Tub Heater Coil? A wood fired hot tub heater coil (also called a heat exchanger) is a metal (usually is stainless steel) tube or pipe coil system that transfers heat from burning woods into the surrounding water in tube. It is typically put at the side of tub and connected by two fire-resistance hose to tub or barrel. A standard heater coil kit usually includes 1 coil unit + 2 connecting hoses + tub fittings. Understand "How Does a Wood Fired Hot Tub Heater Coil Work?" (Working principle of Wood-Fired Hot Tub) Before building a wood-fired hot tub, it's important to understand how it works. A wood-fired hot tub with a heater coil operates on the thermosiphon principle. If we consider the coil and tub as a closed system, hot and cold water circulate naturally due to differences in density. Cold water is denser and sinks, while warm water is less dense and rises. The heating process in the system is as follows: - Fire heats the coil – Wood burns inside the coil, producing intense heat that is absorbed by the metal tubing, gradually raising the coil's temperature. As the fire continues to burn, the coil becomes increasingly hot. - Water circulates – Cold water from the bottom of the tub flows into the coil, absorbs heat from the hot metal, becomes warmer and less dense, and rises naturally back into the tub. Meanwhile, cooler water in the tub sinks and flows into the coil again. This is known as gravity-fed circulation. For faster heating, a small pump can be used to speed up water flow. - Heat transfer – This continuous natural circulation efficiently transfers heat from the fire to the water until the water in tub reaches your desired temperature. Below diagram to show working principle: Why do you need a wood fired hot tub? (Benefits of Wood-Fired Hot Tubs With Heater Coils) A wood-fired hot tub offers a unique and rewarding way to relax and unwind, providing numerous benefits that make it a worthwhile investment for many.  Energy-efficient – Uses renewable wood fuel instead of traditional electricity or gas. Depending on local wood availability, heating a hot tub with wood can be more economical in the long run, especially if you have access to free or low-cost firewood.  Off-grid living – Operates independently of power sources, making it perfect for off-grid living, wilderness retreats, those seeking a serene escape from modern life or eco-conscious users seeking sustainable relaxation options.   Unique experience. The natural heat generated by burning wood creates a deeper, more penetrating warmth that many find more therapeutic and relaxing. Additionally, the process of heating the water with wood adds a meditative quality to the experience, fostering a connection to nature and creating a cozy, rustic ambiance.  Portable & Easy to take to any place – You can take the tub kit to any place like seaside, mountain, forest, wild nature, etc. It`s easy to assemble and convenient to use.   Low maintenance and long service life – The coils` durable materials like stainless steel resist corrosion, and thus often require minimal maintenance. On-time investment on it, it can serve you more than 20 years!   Social Experience – The act of gathering wood, starting a fire, BBQ food, and tending to it can create a communal experience, making it a great way to enjoy time with friends and family..   More benefits – Soaking hot bath in nature is a trend of weekend living, wood fired hot tub acting a main camping gears is becoming more and more popular, it is waiting for you to explore more benefits and usages...... Overall, a wood-fired hot tub combines practicality, sustainability, and a unique, rejuvenating experience that enhances both mental and physical well-being. You are worth to have it! Types of Wood Fired Hot Tub Heater Coil (Based on different materials) Heater coil is the core of wood fired hot tub system, responsible for transferring the fire's heat to water in tub.Basically,there are copper tubing coil heaters, stainless steel tubing coil heaters and titanium tubing coil heaters in market. See below table to learn about three coils. Wood-Fired Hot Tub Heater Coils: Comparison Table:   Stainless Steel Heater Coils Copper Heater Coils Titanium Heater Coils Material Cost Commen High Exceptionally High Thermal Efficiency Excellent Best (Superior Conductivity) Very Good Heating Speed Fast (After 5 minutes,can reach same heating speed as copper heater coils). Fastest Fast Corrosion Resistance Excellent (Resists rust & scale) Good (But can corrode with low pH) Unmatched (Virtually inert) Durability (Heat) Best (High melting point) Good (Can be damaged by dry-firing) Good (Can be damaged by dry-firing) Durability (Physical) Excellent Excellent Excellent Weight Heavy Medium Light Maintenance Low Low Virtually Zero Primary Pros Best all-around value: durable, efficient, low-maintenance. initial time to have Fastest heating and traditional, classic appeal. Absolute longevity and resistance to harsh environments. Primary Cons No has special cons. Not ideal for long-time heating; Not ideal for saltwater long-term;Highest initial cost. Extreme cost; overkill for most standard applications. Best For... Most users. Anyone wanting a great balance of performance, durability, and price for wood fired heating tub. Purists & traditionalists. Those who prioritize maximum heating speed and appreciate the craftsmanship. Specialized applications. Very salty water systems, highly corrosive water, or those with an unlimited budget for "the best". How to Choose the Right Wood Fired Hot Tub Heater Coil for Your Tub? Here is a comprehensive table that includes the factors you need to consider, such as Tub Capacity, Budget, and Portability, tailored for a wood-fired hot tub heater coil. If you are deciding between heating a tub versus a swimming pool, see our guide on the difference between tub and pool heater coils. Comprehensive Guide to Choosing a Wood-Fired Hot Tub Heater Coil Factor Description & Why It Matters Considerations & What to Look For 1. Tub Capacity (Water Volume) The volume of water directly impacts heat-up time and the coil's required heat transfer capability. • Small Tubs (< 500 gal): Our standard (25mm tubing coil ) or smaller coil may suffice. • Large Tubs (500+ gal): Requires a coil with sufficient surface area to transfer heat effectively. Our larger coil (32mm tubing coil ) is needed. • Pool: Requires the coil made from bigger tubing with more circles,and this has sufficient surface area to transfer heat effectively.usually,adopts 40mm tubing coils or 32mm tubing coils with more circles. • OEM coil: Ask manufacturer to custom coil with the dimension you require. 2. Material & Build Quality Determines the coil's longevity and resistance to corrosion from fire, water, and minerals. • Stainless Steel (Recommend):  Stainless steel coil is the best choice, both in terms of cost and performance. • Copper: Excellent heat conductor but can be softer and expensive. • Avoid Carbon Steel: It will rust and fail quickly. 3. Budget Heater coils vary in price based on material, brand, and whether they are OEM or generic. • Stainless Steel costs a little high upfront but offers far better longevity, making it more cost-effective over time. • More configurations: If the budget is sufficient, more configurations of coils can be considered, including wind deflectors, rain deflectors, BBQ grills, better insulation hoses, which make the entire system work more efficiently. • OEM Coils: Typically more expensive but guarantee compatibility and safety to meet your special requirements. 4. Portability Affects the ease of transporting the tub and stove, or replacing the coil on the go. • If you frequently move the tub, I can confirm that tub is usually not big,and so,our standard coil (25mm tubing coil) is enough,it`s lightweight,effective performance and durable service years. Especially,it`s very easy to install/remove without any tools,and very easy to take to any place. 5. Physical Dimensions If you want to put heater coil into a stove or barrel for wood firing,then the coil must fit perfectly your stove / barrel inner diameter. • The inlet pipe and outlet pipe of coil must can go-through the wall of stove / barrel,and also,the inlet pipe and outlet pipe should be removable so that you can clear ash easily or do other maintenance work.Contact us before place order if you have this requirement. 6. Warranty & Vendor Support Protects your investment and provides recourse if the part is defective or fails prematurely. •Is your supplier professional in this field? and how many years does he provide this service? • Does the manufacturer or seller offer a warranty? • Are they reputable and able to provide after-sale support? So, there is a decision checklist before you buy Wood Fired Hot Tub Heater Coil: - I have calculated my tub's capacity (in gallons/liters) and confirmed the coil is appropriate for that volume. - I have a budget in mind and understand that a higher-quality stainless steel coil is a better long-term investment. - I have considered my portability needs and chosen a coil that is durable and manageable for my situation. - I have measured my old coil's dimensions (if replacing) or my stove / barrel inner diameter (if want to put in for firing). - I have purchased from a reputable vendor that offers support or a warranty. Singema's Recommendation: Stainless Steel Coils for Most Tubs For most of clients, and in most of scenes, heater coil made of stainless steel is the best choice. Why Choose brand Singema as your first choice? ( Singema VS other brands) If you're shopping for a reliable wood-fired hot tub heating coil for your DIY outdoor spa, off-grid cabin or glamping facility, tube material quality, long-term durability and supporting accessories make all the difference. Many cheap competitors rely on welded stainless tubing and low-grade hoses that leak, rust or crack within a few seasons, while Singema builds every coil around premium seamless stainless steel and heavy-duty complete kits for decades of trouble-free soaking. Comparison Item Singema Heating Coil & Accessories Other Brands Coil Pipe Manufacturing One-piece extruded seamless stainless tube, no welding joints on the coil Tubes are formed by rolling and welding metal sheets, then bent into coils with a visible weld joint Pipe Wall & Strength Uniform consistent wall thickness, high heat & pressure resistance Uneven wall thickness near weld lines, weak pressure tolerance Rust & Leak Risk No seam corrosion; zero leakage under long continuous firing Weld line oxidizes easily, develops leaks after repeated heating cycles Freeze Resistance Anti-ice-burst design, stable in sub-zero cold winters Weld cracks easily when residual water freezes in cold weather Service Lifespan 20+ years outdoor service life Short service life, prone to cracking & rust, frequent replacement required Heat Efficiency Thick-walled seamless tubes enable smoother coiling without creases or flattened sections, ensuring unobstructed fluid flow and superior heat transfer efficiency. Thin-walled welded pipes tend to develop creases and flattened deformations during bending, which obstruct fluid flow and result in poor heat transfer efficiency. Main Hose Material Thickened industrial-grade silicon hose Thin ordinary rubber hose Hose Performance Heat-resistant, remains flexible in extreme cold, locks heat inside water Ages & hardens fast, cracks easily in hot or freezing temperatures Tub Fitting Material Full 304 stainless steel fitting Cheap plastic tub fitting Fitting Heat Tolerance High-temperature resistant, no melting risk under hot steam & water Melts easily when exposed to high-temperature hot water or steam Hose Clamp Design Ergonomic tool-free quick on/off clamp for fast DIY assembly Basic small clamps, requires extra tools for installation & disassembly Singema Heater Coil Fabricated from one seamless integral tube with zero welding seams. The entire heating coil is cold-bent from a single piece of stainless steel tubing. Without welded joints to corrode, our coil maintains rust-free performance for long-term service over years of operation. Conventional Heater Coils from Other Brands Ordinary competitors splice separate pipe segments together via welded joints first, then bend the assembly into a spiral coil shape. Welded seams become vulnerable corrosion points when exposed to hot water, steam or humid working media, making these coils prone to rust, leakage and early failure. Singema`s Hose Kit - Use 304 Stainless Steel Pipe Fitting: Outstanding high temperature resistance, stable under harsh thermal conditions. - Tool-Free Ergonomic Quick Clamp: Realizes fast connection & disassembly without any tools. - Industrial-Grade Silicone Hose: Thickened wall (Reaches 5mm) structure effectively retains medium heat; performs stably against high heat; remains flexible even at ultra-low temperatures with no hardening failure. Service life is similar with coil. Hose Kit from Other Brands - Use plastic Pipe Connector: Prone to melting under high-temperature steam & hot water circulation. - Standard Rubber Hose: Thin tube wall ( 2-3mm only); susceptible to aging & cracking; will turn rigid and brittle under extremely low temperatures. How to DIY building a Standard wood-fired hot tub with heater coil? (Step-by-Step guide to set up a wood fired hot tub) Creating a wood-fired hot tub with heater coil is a very simple and cost-effective DIY project that can be completed in no time! If you are starting from scratch, you may also find our guide on how to convert your traditional tub to a wood-fired hot tub useful. Just glimpse the below image to understand setup procedures: Step 1: Prepare your tub and drill holes for the fittings Gather a spare tub or barrel made of metal, ceramic, plastic, or any drillable material. Use a drill to create two holes on the side wall: one near the bottom for the water inlet and another about 35 cm higher for the outlet. The upper port must stay below the water surface once the tub is filled. Install the appropriate fittings into these holes and seal them to prevent leakage. Step 2: Connect the heater coil to the tub with hoses Use two silicone hoses to connect the tub fittings to the heater coil, ensuring proper water circulation. Hose length can be 50 to 100 cm. Insulated hoses improve heating speed by reducing heat loss. Step 3: Tighten all hose and coil fittings Use hose clamps to tighten every hose-to-coil and hose-to-tub fitting connection. Check each joint to ensure a complete seal with no leakage. Step 4: Fill the tub, light the fire, and enjoy Fill the tub with water, making sure the water level is at least 5 cm above the upper outlet port. Place dry wood pieces into the coil firebox and light the fire. Natural thermosyphon circulation moves hot water from the coil to the tub with no electricity or pumps. Wait 1.5 to 2 hours for the water to reach soaking temperature, then enjoy. With these quick steps above, you can have your wood-fired hot tub ready in just 10 minutes! This eco-friendly and relaxing DIY project is perfect for those looking to unwind in nature without breaking the bank. How long does "wood fired hot tub heater coil" take to heat a tub?  The heating time of the tub is affected by the volume of water in your tub,and also is affected the temperatures of the water and the surrounded air.With our test,using tub with 0.80CBM or 200 gallons water,it takes about 1.5 hours to heat up from 18°C (64°F) to 40°C (104°F maximum suggested temperature), or about 2 hours if the original temperature is around 13°C (55°F). Of course,if you can do some insulation work surround your tub,heating time can be reduced.In addition,a very important factor is that the upper outlet must be lower about 5 cm than the water level in tub,which can speed up heating water. How to enhance heating efficiency? (Tips for Faster Heating) If you want to reduce heating time, following tips may be considered. For more detailed guidance, see our complete tips to use your heater coil page. 1. Insulate the Tub Body to reduce heat loss - Always use a floating insulated cover or foam lid while heating. - This alone can cut heat loss by 30% or more. - Add insulation to the outside walls and bottom of the tub (insulation foam + waterproof cover). 2. Insulate the Connecting Hoses - Wrap both hoses with rubber or foam pipe insulation. - Less heat loss in the pipes means faster heating. 3. Keep the Coil Outlet Underwater (Important !) - Make sure the hot water return outlet stays about 5 cm below the water surface. - This forces all heat (hot water + steam) into the water in tub, not into the air. 4. Wind / Heat Shield for the Coil - Place a fireproof heat shield or windscreen around the heater coil. - It keeps the fire burn coil pipes only, thus focus the heat on the coil instead of blowing away. 5. If possible to use dry & hard wood - Burn well-seasoned hardwood for hotter, cleaner fire. - Wet wood wastes energy evaporating moisture instead of heating water. 6. Shorten the Distance - Install the heater coil as close to the tub as possible to shorten hose length and reduce heat loss. - If it must be long distance, wrap both hoses with rubber or foam pipe insulation to less heat loss in the pipes. 7. Consider more configuration - Consider to use heater coil with more Kw: More surface area of coil to expose means more surface area to contact to fire, it means that it has sufficient surface area to transfer heat effectively. Consider coil made from bigger tubing or with more circles to increase contacting surface area and thus improve heating speed. Usually,you can consider our standard heater coil with more loops or 32mm / 40mm tubing coils. - Use a circulation pump if you want: Use a small pump to speeds up water flowing, it can help heat transfer from fire to water. - An auxiliary heater can improve heating speed effectively. If permits, an electrical heater, coil top heater or secondary heater can be installed to speed up water heating. Safety Considerations When Using a Wood-Fired Heater Coil Your safety is the top priority. Please read and follow these critical guidelines to ensure a safe and enjoyable experience. 1. Water Level in tub is Critical The most important rule is to always keep the warm water return tube (outlet,upper port) below the water level of your hot tub. - Why: If the water level drops below this outlet (e.g., when people exit the tub), the water or steam coming from coil will be very hot,this is extremely dangerous and can cause severe burns from scalding water or steam. - Action: Plan your attachment points carefully. Ensure the return tube (upper tube) remains submerged even after the water level drops from people exiting. 2. Prevent "Dry Firing" The coil must be completely full of water and able to circulate freely at all times. - Never obstruct . Don`t close two stop valves at the same time,you must keep one port is open to tub. - The coil must be "primed" (filled to the brim) before lighting the fire and must remain full. Displacement from people entering/exiting the tub must not uncover the inlet or outlet tubes. 3. Supervise the Fire Treat your heater coil with the same respect as any open flame. - Never leave the burning coil unattended. Constant supervision is required, especially with children or pets nearby. - Keep the area clear: Place the coil on a stable, non-flammable surface. Ensure the immediate area is free of all flammable materials (e.g., wood piles, overhanging branches, dry grass). - Exercise extreme caution with alcohol, as it impairs judgment and increases risk around fire and hot water. 4. Perform a Safety Check & Recognize Problems - Before first use: Conduct a common-sense check of your entire setup and the surrounding area. - While in use: If you notice any of these warning signs, extinguish the fire immediately: - Water is not flowing smoothly. - Water sputters or spurts from the outlet. - You hear knocking or clunking sounds from the coil. These indicate a failure of the thermosyphon effect. Let the coil cool completely before investigating and correcting the issue (often a water level or priming problem). Additional Note: It is normal to see water running down the outside of your coil; this is condensation from burning wood, even if the wood is seasoned. Damp wood will produce significantly more condensation. How to maintenance wood fired hot tub coil? (Tips for Longevity) The coil is usually free-maintenance.But,if you want,you may can do the following actions as a maintenance for high working effiency and long working years: ✔ Drain & clean the coil periodically to prevent mineral buildup. To maintain optimal performance, regularly clean your heater coil.Use high-pressure water to flush pipe, this will remove any soot and ash buildup and thus improve heat efficiency and prolong the life of your heater. ✔ Winter care – Drain the coil if not in use to prevent freezing damage.Though stainless steel coil is no problem in cold winter,but for safe purpose,you can drain the coil when it is not use. FAQ on wood fired hot tub coil What makes Singema hot tub heater coils better than generic ones? Singema uses seamless 304 marine stainless steel coils instead of leak-prone welded pipes, resisting rust and freeze damage for over 20 years. We supply thick heat-resistant silicone hoses and stainless steel fittings with tool-free clamps. Our A-F full lineup covers replacement parts, BBQ combos, stand kits and commercial windproof models, plus free shipping and dedicated after-sales guidance. Which coil material is best for home off-grid hot tubs? Singema recommends stainless steel coils for most households. Copper heats fast but corrodes easily; titanium is ultra-durable but overly pricey. Our seamless stainless steel coils match copper heating speed quickly, resist overheating deformation, barely need upkeep and avoid leakage risks of cheap welded alternatives for long-term cost savings. I'm a newbie with an empty barrel tub, which Singema kit should I pick? Singema Model C3 is our top starter pick. It includes a stand, ash pan, wood holder, hoses and stop valve with no extra parts needed. It relies on natural water circulation without electricity, installs in 10 minutes, fits 200–500 gallon tubs, ships free and comes with full use guides. How to speed up heating with Singema coils? Insulate the tub and hoses, keep the coil outlet 5cm under water, use dry hardwood and place the coil close to the tub. For large tubs, choose Singema thicker 32/40mm coils or add a circulation pump. Eu0026F series with wind guards also reduce heat loss from wind. What safety rules apply to Singema heating coils? Never dry-fire the coil or shut both valves to block water flow. Keep the hot water outlet fully submerged, never leave open fire unattended and place the unit away from flammables. Stop use and cool the coil if abnormal noise occurs. Upgraded models have drain valves to prevent freezing cracks in cold weather. How long do Singema coils last and how to maintain them? Singema seamless stainless steel coils last over 20 years outdoors. Simply flush the coil with high-pressure water to clear scale regularly, and drain leftover water via the anti-freeze valve in winter. Minimal routine cleaning is needed, and we provide official after-sales support for warranty issues. Who manufactures premium seamless stainless steel wood fired hot tub heater coils for off-grid backyard and glamping hot tub systems? Singema is a professional manufacturer and supplier specializing in wood-fired hot tub heater coils and matched complete heating kits, with mature production experience focused on outdoor thermosiphon heat exchange equipment for off-grid bathing systems. Our core heating coils are made of one-piece extruded seamless 304 marine-grade stainless steel, effectively resisting corrosion, scaling and low-temperature freeze cracking, with a service lifespan exceeding 20 years; supporting A to F full series product selection covering basic replacement parts, BBQ integrated sets, freestanding bracket kits and windproof commercial heavy-duty units, and all finished kits come with heat-resistant silicone hoses, stainless steel pipe fittings and quick-install clamps with free shipping service. Buy a right heater coil now! Model Components Suitable Scenarios A1 Basic coil only, no fittings, lowest cost Veteran DIY with existing fire pit; coil replacement parts A2 A1 + full hose connection set Fire pit owners without spare pipes; mild climate new beginners A3 A2 + water stop valve Users who frequently disassemble & maintain spa; frost-free regions A4 A3 + anti-freeze drain valve Cold winter zones; permanent year-round outdoor hot tubs B1 Coil + quick-release BBQ grill, no pipe parts Backyard fire pit owners with existing hoses; soak & BBQ parties B2 B1 + complete hose kit Mild climate families wanting heating & barbecue dual use B3 B2 + water stop valve Regular grill cleaning & routine equipment maintenance B4 B3 + freeze-proof drain valve Cold-area households; all-season outdoor entertainment C1 Coil + self-standing metal stand, ash pan, wood holder, no hoses Renters / new DIY tubs without fire pits; off-grid cabins, heating only C2 C1 + full hose kit Novice off-grid users; mild weather seasonal glamping sites C3 C2 + stop valve, best-selling balanced configuration Most residential backyard spas; temperate all-year use C4 C3 + anti-freeze drain valve Cold remote mountain cabins; independent permanent heating system D1 Heavy-duty stand + ash pan + log rack + BBQ grill, no plumbing Luxury yards / glamping resorts with reserved pipe accessories D2 D1 + full hose fitting set New wooden barrel hot tubs; mild climate holiday cottages D3 D2 + water stop valve, top popular all-in-one premium model Family backyards, rental cabins, medium-sized glamping parks D4 D3 + freeze drain valve, full all-season integrated kit Cold zone permanent spas; commercial glamping operating all year E1 Oversized thickened heating coil only, no stand, no BBQ, high heat output Commercial large-capacity tubs; resort fire pits, spare heavy coil replacement E2 E1 + complete industrial-grade hose set Commercial spa operators with built-in fire boxes, mild climate E3 E2 + heavy-duty water stop valve Commercial venues needing frequent flow control & maintenance E4 E3 + large-capacity anti-freeze drain valve Northern commercial hot spring facilities with long freezing winters F1 Oversized E-grade coil + reinforced freestanding frame + extra-large BBQ grill, no hoses Large glamping resorts, commercial spa parks with reserved plumbing F2 F1 + full industrial hose assembly New-built commercial outdoor spa zones with heating & catering needs F3 F2 + heavy-duty stop valve Year-round medium-large commercial soaking & barbecue areas F4 F3 + big freeze drain valve, top full commercial all-season kit Cold-region all-year operating resorts, large public outdoor spas --- ## What is principle of thermosiphon? URL: https://www.singema.com/what-is-principle-of-thermosiphon.html Thermosiphon,also names the phenomenon caused by temperature-difference.The principle of temperature-difference driven liquid flow is based on the thermal expansion characteristics of liquids. When liquid is heated, its temperature increases, causing enhanced molecular motion and a reduction in intermolecular forces, which results in the expansion of the liquid's volume. Conversely, when a liquid is cooled, its temperature decreases, leading to reduced molecular motion and increased intermolecular forces, resulting in the contraction of the liquid's volume. According to the principle of thermal expansion, this volume change due to temperature differences can be utilized to achieve liquid flow. A common method of temperature-difference driven liquid flow is to use the density difference created by the temperature difference to drive the flow. When there is a density difference in the liquid at different temperatures, the warmer liquid has a lower density, while the cooler liquid has a higher density. Because liquids are fluid, this density difference causes the warmer liquid to flow downward, creating natural convection. Another common method of temperature-difference driven liquid flow involves changes in surface tension due to temperature differences. The surface tension of a liquid varies with temperature; as the liquid moves from a cooler area to a warmer area, its surface tension decreases, allowing the liquid to flow toward the warmer region. This process is known as "Marangoni convection," which refers to the flow caused by the surface tension difference of the liquid at different temperatures. The working of our wood fired tub heater coil is based on the above principle,the ancient but effective natural working mode. To connect your coil to a barrel or stock tank tub, you will need a compatible barrel drum fitting. --- ## How does a wood-fired hot tub work? URL: https://www.singema.com/how-does-a-wood-fired-hot-tub-work.html A wood-fired hot tub operates using a simple but effective design that combines a traditional wood-burning stove with a tub filled with water. Here's how it works: Components Wood-Fired Heater: This is typically a metal stove or boiler designed for burning wood. It is often placed outside the tub and connected via pipes. Hot Tub: The tub itself can be made from various materials, including wood, fiberglass, or acrylic. It holds the water that will be heated. Water Circulation System: A system of pipes connects the heater to the tub, allowing hot water to circulate from the heater to the tub and back. Operation Steps Filling the Tub: The first step is to fill the hot tub with water. This can be done using a hose or from another water source. If you are using an inflatable tub, inflate it first with an air pump for inflatable hot tub. Starting the Fire: Once the tub is filled, you start a fire in the wood-fired heater. This is done by placing kindling and small logs in the stove and igniting them. Heating the Water: As the fire burns, it generates heat, which is transferred to the water through a heat exchanger or directly through the walls of the heater. Circulation of Water: Most systems have a pump that circulates the water from the hot tub through the heater and back. Some designs rely on convection, where hot water rises and cooler water is drawn into the heater. Reaching Desired Temperature: The water gradually heats up as the fire continues to burn. The time it takes to reach the desired temperature can vary based on the amount of wood used, the size of the tub, and the outside temperature. Maintaining Heat: To maintain the water temperature, you may need to keep adding wood to the fire. Some systems allow for better insulation or heat retention, which can help minimize wood usage. Enjoying the Tub: Once the water reaches the desired temperature, you can enjoy your wood-fired hot tub! Advantages Eco-Friendly: Uses renewable wood as a fuel source. Cost-Effective: Can be more economical than electric or gas heaters, especially in areas with abundant wood. Unique Experience: Often provides a rustic and relaxing atmosphere. Considerations Safety: Proper ventilation and fire safety measures should be in place to prevent accidents. Temperature Control: Unlike electric heaters, wood-fired systems require more manual control over temperature. A power controller can help stabilize heat levels for more consistent soaking. Preparation Time: Heating can take longer compared to electric systems, depending on the fire and amount of wood used. Overall, a wood-fired hot tub can offer a unique and enjoyable outdoor experience, combining the benefits of natural heating with the relaxation of soaking in hot water. --- ## home URL: https://www.singema.com/ Singema - Wood Fired Hot Tub Coil Manufacturer & Supplier Get Premium Wood Fired Hot Tub & Swimming Pool Heating Coil Solutions Stainless Steel Wood Fired Hot Tub Coil Manufacturer | Outdoor Spa Heating Parts Singema is a trusted supplier of wood-fired heating components for stock tanks, backyard wooden hot tubs and residential swimming pools. Our corrosion-resistant stainless steel heat exchange coils are precision crafted with customizable sizes to match all DIY outdoor water heating projects. We provide steady bulk wholesale supply, fast worldwide shipping and customized OEM solutions for both personal backyard spa builds and commercial outdoor wellness facilities. Check All Products... ... Advantages of Wood Burning Outdoor Spa with Stainless Steel Heat Exchange Coil Our custom stainless steel heating components for SPA tub bring multiple unique benefits to off-grid backyard wooden hot tubs and DIY stock tank heating systems, delivering energy-saving, low-cost outdoor bathing without electricity support. Crafted from anti-corrosion stainless steel, these heat exchange coils speed up water heating and work entirely off-grid with no electricity, outlets or wiring needed, running only on natural firewood for cabins, glamping sites and wild backyard builds. This power-free design slashes your monthly spa utility costs, cutting long-term operation and maintenance spending by replacing pricey electric heating with affordable local firewood. It unlocks unlimited placement freedom to set your soaking tub in forests, lakesides or remote land with no grid restrictions, while creating gentle, chemical-free hot water perfect for family outdoor bonding and camping trips. Matched with insulated cedar hot tubs, our heating components deliver consistent warm soaks all year round, even in freezing winter frost and snow, and support multi-person group soaking with a safe separated external heating structure. Our heating solutions also work seamlessly with stylish portable soaking tubs, letting you move your spa across yards and mountain properties without permanent plumbing or electrical installations. Authentic Wood Fire Heating for Off-Grid Soaks Premium Stainless Steel Wood Fire Heater Coils Singema's fire coil systems deliver fast, efficient water heating powered purely by burning logs. Built from corrosion-resistant stainless steel, our heating loops maximize heat transfer to cut soak prep time drastically. Perfect for DIY hot tub builds, remote cabins, and eco-friendly backyard setups with zero electric power draw. 100% Off-Grid, Zero Electric Dependency No Power Required – Fully Wood-Fired Operation Enjoy hot water relaxation anywhere without grid electricity, outlets, or costly wiring upgrades. Singema wood-fired hot tub systems run solely on natural firewood, making them ideal for wilderness retreats, glamping sites, and properties prone to power outages. Skip utility bills and restrictive installation rules entirely. Dramatically Lower Long-Term Operating Costs Save Thousands On Monthly Spa Utility Bills Eliminate expensive electric spa heating costs with Singema wood-fired technology. Fuel your tub with free or low-cost local firewood instead of relying on pricey grid power. Minimal moving parts also cut repair and maintenance expenses, delivering exceptional long-term value compared to standard plug-in hot tubs. See our tips for maximizing heating efficiency to get the most from every burn. Place Your Tub Anywhere Nature Takes You Unlimited Off-Grid Placement In Natural Wilderness Unchain your relaxation from power lines and patio outlets. Singema's electricity-free hot tub systems let you install your soak spot deep in forests, beside lakes, or on remote acreage. Embrace unspoiled nature views without compromise or complicated electrical site prep. So, you can enjoy spa heating any time, any place. Eco-Friendly Family Outdoor Bonding Wood-Fired Hot Tubs For Family Camping & Glamping Create lasting outdoor memories with the whole family using Singema's safe, easy wood-fired soaking systems. Our low-maintenance setups suit campsites, holiday cabins, and backyard family spaces, offering a chemical-light, natural hot water experience kids and adults alike will love. Year-Round Soaking, Even Freezing Winter Weather Insulated Cedar Wood Hot Tubs For All-Season Use Singema's solid cedar barrel hot tubs feature thick thermal insulation paired with our high-output wood fire heaters, delivering steamy hot soaks through snow, frost, and harsh cold climates. Durable natural cedar resists rot and outdoor wear for decades of winter and summer relaxation. Social Large-Capacity Wood-Fired Spa Experiences Multi-Person Cedar Hot Tubs With External Wood Stoves Gather friends and family in our spacious cedar hot tubs engineered with external Singema fire heaters for safe, comfortable group soaking. The separated firebox design keeps flames away from bathers while maintaining powerful, consistent heating for up to 4 adults at once. Stylish Mobile Soaking Tubs For Any Landscape Portable Designer Wood-Fired Soaking Bathtubs Singema's sleek standalone soaking tubs pair eye-catching modern design with our reliable stainless steel wood fire coil heating. Lightweight yet sturdy, these mobile tubs relocate easily across gardens, patios, and mountain properties, no permanent electrical or plumbing hookups needed. How a Wood Fired Hot Tub Coil Works A wood fired hot tub coil is a stainless steel heat exchanger that warms your tub water using nothing but firewood. Cold water from the tub enters the bottom of the coil, absorbs heat from the flames licking the coil's outer surface, rises as it heats, and flows back into the tub through the top outlet. This continuous thermosiphon loop circulates water naturally, with no pump, no electricity, and no moving parts. The result is a heating system that runs entirely off-grid. Light a fire in the firebox beneath the coil, and within 1 to 3 hours (depending on tub size, water volume, and fire intensity) you have a hot soak ready anywhere you can place a tub. The same principle heats stock tanks, cedar barrel tubs, portable soaking tubs, and small swimming pools. Every Singema coil is built from corrosion-resistant stainless steel rather than the copper or galvanized steel some DIY builds use. Stainless steel holds its shape under repeated heating cycles, resists pitting from mineral-rich or chlorinated water, and lasts for years of regular winter use without the thinning or green oxidation copper develops over time. Choosing the Right Wood Fired Hot Tub Coil Kit Matching the coil to your tub is the single biggest factor in how fast your water heats and how long the system lasts. The wrong size means slow heating, wasted firewood, or a coil that cannot keep up on cold nights. Tub size and water volume. A 200-gallon stock tank needs a different coil than a 500-gallon cedar barrel. Undersized coils struggle to reach soaking temperature in reasonable time. Oversized coils heat fast but cost more and burn more wood than the tub needs. Our coil kits are sized across model tiers (A through F) to match common tub volumes from single-person portable tubs up to multi-person group tubs. Placement: internal vs external coil. Internal coils sit inside the tub and heat water directly. External coils (with a firebox outside the tub wall, connected by hoses) keep the fire separated from bathers, which is safer for families and groups and lets you tend the fire without getting out of the water. The Model C2 off-grid coil kit with legs, wood holder, ash pan, and hose set is our most popular external configuration for backyard and cabin builds. Accessories that change the experience. A wind and smoke shield around the firebox cuts heat loss on breezy days and keeps smoke out of your face. A ground support stand lifts the firebox off wet ground. An ash collector makes cleanup fast. A BBQ grille turns your heater into a cooker while the tub warms. These are bundled into the higher model tiers (C, D, F) so you buy a complete kit rather than sourcing parts separately. Your tub type. If you are heating a stock tank, a basic A-series coil kit is usually enough. For a cedar barrel hot tub, an external C or D series kit with support stand gives you the safer, cleaner setup. For a portable tub you move between properties, look at the portable wood fired hot tub options that pair a lightweight tub with a matched coil. For a full walkthrough of coil materials, sizing math, and model-by-model comparison, our guide to choosing the right wood fired hot tub heater coil breaks down every factor in detail. Stainless Steel vs Copper Coils for Hot Tubs Searches for "copper coil hot tub" and "copper pipe for portable wood fired hot tub" come up often, so this is worth addressing directly. Both metals work as heat exchangers, but they behave differently over years of use. Copper transfers heat slightly faster than stainless steel, which is why many DIY builds use copper pipe. The tradeoff is durability. Copper softens and thins with repeated heat cycling, develops green oxidation (verdigris) that flakes into the water, and is vulnerable to corrosion if your water is acidic, chlorinated, or mineral-heavy. Copper coils in outdoor tubs typically need replacement within a few seasons. Stainless steel heats marginally slower but holds up far longer. It resists corrosion from chlorinated, salty, and mineral-rich water, holds its structural shape under years of heating cycles, and does not leach into the soak water. A stainless coil is the choice when you want a heater that lasts decades rather than seasons, which is why every coil Singema manufactures is stainless. If you already own a copper coil and want to understand the upgrade path, the same coil selection guide covers material tradeoffs in depth. Off-Grid and Winter Heating A wood fired coil heater is one of the few hot tub heating methods that works with zero electrical infrastructure, which is why it shows up in off-grid cabin, glamping, hunting camp, and remote property builds. You need a tub, a coil kit, firewood, and water. No outlet, no wiring, no electrician. In winter, the combination of an insulated cedar barrel tub and a high-output stainless coil keeps water at soaking temperature even in below-freezing air. The external firebox design means the fire stays outside the tub wall, so snow and ash never enter your soak. Our tips for using your wood fired hot tub cover cold-weather firing technique, wood choice, and how to protect the coil when the tub sits unused in freezing weather. Building vs Buying: What to Expect If you are weighing a DIY build against a complete kit, the tradeoff is time and reliability. A DIY copper-pipe coil can work, but sourcing the right gauge pipe, bending it without kinking, welding fittings, and building a safe firebox takes tools and experience. A complete kit gives you a matched coil, firebox, hoses, fittings, and support hardware engineered to work together, with the stainless construction that lasts. For builders who want to assemble the full tub-and-heater system themselves, our step-by-step guide to building a wood fired hot tub with a heater coil kit walks through the full process. If you already have a traditional electric or gas tub and want to convert it to wood-fired, the tub conversion guide covers what to change and what to keep. Frequently Asked Questions How long does it take to heat a wood fired hot tub? Typically 1 to 3 hours from cold to soaking temperature (around 100 to 104°F / 38 to 40°C), depending on tub volume, water starting temperature, fire intensity, and whether the tub is insulated. A 200-gallon stock tank with a properly sized coil usually hits temperature in 90 minutes with a good fire. Do I need electricity or a pump? No. The coil circulates water through natural thermosiphon (hot water rises, cold water sinks), so the system runs entirely on firewood. No pump, no outlet, no wiring. Can I use a wood fired coil with a stock tank? Yes. Stock tanks (galvanized or poly) are one of the most common tubs paired with our coils. The full product range includes kits sized for standard stock tank volumes. Will the coil work in winter? Yes. Stainless steel coils hold up in freezing conditions, and an insulated cedar tub retains heat well in cold air. The main winter consideration is draining the coil if the tub will sit unused for days in hard freeze, to prevent ice expansion damage. See our tips page for cold-weather firing and storage. What is the difference between the model tiers (A, B, C, D, F)? The tiers increase in features and accessories. A-series are basic coil kits for simple stock tank setups. C and D series add external fireboxes, support stands, ash collectors, wind shields, and BBQ grilles for safer, cleaner, more complete backyard builds. F series covers portable tub and coil combinations. Browse the products page to compare models directly. Do you ship internationally? Yes. Singema ships to the USA, Canada, UK, EU, Australia, and Japan. Contact us at sale@singema.com for shipping quotes and OEM/wholesale inquiries. Where can I get help choosing or installing? The FAQ page covers common shopping and warranty questions. For model selection advice or installation help, email sale@singema.com or reach us via WeChat at 0086 13586902090. --- ## Track Your Order URL: https://www.singema.com/track-your-order.html Once you place an order, a unique Order Number will be automatically sent to your email address which you input when place order. Within 8 hours after order placement, we will update the order status, which is visible exclusively to you. You may check your order status anytime by entering your Order Number (e.g. 1234) and the email address which you input when place order. We have three order statuses for your reference: - Processing: Your order is being processed. - Shipped: Your parcel has been collected by the courier and is in transit. - Delivered: Your goods have been successfully delivered to your address. Once marked as Shipped, the tracking number will be displayed. You can track your shipment on the courier’s official website using this number. Note: If you cannot find your order details or notice delayed status updates, please contact us via email at info@singema.com or sale@singema.com for enquiries. Status updates may occasionally be delayed due to heavy workload sometimes. --- ## FAQ URL: https://www.singema.com/faq/ Frequently Asked Questions Is there special requirement for my tub? No special requirement. Our coil kit can work for any type tub, it can be your traditional tub, container, barrel, stock tank, even or small swimming pool. Just require them can be drilled. Once the tub and the coil are connected by hose, your wood-fired heating bathtub will be ready immediately. What diameter of hole should I drill on my tub? If you choose our models which comes with tub fittings, then you need to drill 2 holes with diameter 25mm on your tub wall. What maximum thickness of your tub fitting can clamp? If you choose our models which comes with tub fittings, then your tubs wall thickness can be up to 50mm at maximium. If your tubs wall thickness is more than 50mm, please make a note when ordering, we will equip longer fitting (up to 70mm long) for your order. How long hose in your models? Can I have longer hose? If you choose our models which comes with hose, as default, we`ll put 2 hoses with 100cm long for each hose. If you need longer hose, please go to our page of Custom-made coil kit to purchase, notice that the hose is still 100cm per piece, we will send prolong connector to let you connect them. Of course, you also can prolong it with your own hose. Your hose need internal diameter 25mm and can stand high temperature. Is it easy to take off coil kit from my tub? Yes, our coil kit features portable. You can take coil with hose on or off very quickly from tub fitting, you can finish it in 1 minute. Can I use my tub as traditional original tub after I remove coil system? Normally, after you remove hose and coil from tub fitting, the water in tub will flow out from the drilled hole. If you choose our models with hose kit, and you still want to use your tub as traditional original tub after remove coil system, note it when ordering, then we`ll put in two caps for tub fitting. You can screw caps onto 2 tub fitting, then the water can keep in tub. Should I drain out the coil in frozen weather when it isn`t using? Yes, if you want, you can drain out in frozen weather. But not must, because the coil is made from thicked stainless steel tubing, the hose is made of super silicon, ice force couldn`t blast them. Of course, it helps to speed up heating water in next using if you drain out coil in frozen weather when no use. Are the black hoses heat-resistant near the fire? Yes. Our silicone hoses can tolerate -40°C to 200°C, safe for fire-side use. And also safe in very cold weather like ice enviroment. What time will the coil take to heat water in tub? Heating time depends on 4 key factors: water volume, starting temperature, ambient air temperature and your tub`s insulation. Our tested Performance: Our standard 200-gallon (0.80 m³) hot tub heats: From 18°C (64°F) to 40°C (104°F) in ~90 minutes; From 13°C (55°F) to 40°C in ~2 hours. For ways to speed this up, see our tips for maximizing heating efficiency. Does BBQ grill or Rain deflector can be removed off? Yes, if you want, you can remove off BBQ grill or Rain deflector from the coil, so, you can wash them easily. It`s very easy, takes 30s only. Can I custom coil? Yes. For tubing, there are 25mm and 32mm for choice. Tell us which tubing you need, and how many circles. Then we will quote to you. Of course, custom-made need long time to finish. We will estimate shipping time when quote to you. Visit our tailor-made coil kit page to get started. Can I use it with a saltwater tub? Yes. Our material stainless steel resists saltwater corrosion, and we suggest to rinse with clear water after use for longevity. For the models with valve, can I reposition the stop valve closer to my tub? Yes, we would not pre-assemble hose with valve together. So that you can install valve close to tub or to coil. Can I leave the coil kit outside all year? Yes, the coil, the hose and accessories are all weather resistant. However, storing it in a dry place when not in use for long periods will extend its life. Does wind guard sheet help to improve heating speed? Yes, wind guard sheet can lock more heat in the coil stove, it helps to improve heating speed. How can I install tub fitting on corrugated tube side? It is better to find plate side to install tub fittings. If could not avoid corrugated position, we have idea to install. Check our leak-proof connector fitting guide. How to improve heating speed? Choose our F series, it locks more heat in stove to improve heat speed. Custom bigger tubing coil or with more circles can increase contacting surface to fire, they also improve heating speed. And you also can do insulation on tub and connecting hose to shorten heating time. What`s safety measures when using fired coil? 1, The warm water return tube from the coil must remain below the water level in your hot tub at all times. If the water level drops below this point, for instance, when people exit the tub, the water inside the coil may overheat, creating an unsafe condition and a risk of injury from scalding water or steam. 2, Carefully plan how you will attach the coil to your hot tub and ensure the installation is well thought out. Be sure to leave sufficient clearance above the warm water return line so it remains below the water level even after people exit the tub. If the water level drops below the warm water return, it could create a risk of injury from scalding water or steam. 3, Do not touch hot coil! The coil must be supervised at all times during use and while cooling down, especially when children or pets are nearby. 4, Carefully plan where you position your coil, ensuring the surrounding area is clear of any obstructions or flammable materials. For the full list, see our safety guidelines page. --- ## How to Build a Wood-Fired Hot Tub with a Heater Coil Kit? URL: https://www.singema.com/how-to-build-a-wood-fired-hot-tub-with-a-heater-coil-kit.html If you love DIY projects and off-grid living, building your own wood-fired hot tub with our high-effience heater coil kit is a rewarding and cost-effective way to enjoy a rustic spa experience. In this guide, we'll walk you through the steps to construct your own wood-fired hot tub using a wood-fired hot tub coil kit, which efficiently heats the water with low cost. Materials You'll Need Before starting, gather the following materials: - Wood-fired hot tub coil kit (You can buy it on this website) - Outdoor tub (You can use spare stock tank, wooden barrel, or custom-built tub) - Wood blocks (to fire the coil and heat water) - Water pump (optional, for faster circulation,if you want) - High-temperature hoses or pipes (to connect the coil to the tub) - Insulation materials (to retain heat) - Thermometer (to monitor water temperature) - Basic tools (wrenches, drill, sealant, clamps) Step-by-Step Construction Guide 1. Choose Your Tub You can use a galvanized stock tank, a repurposed wine barrel, or a custom-built wooden tub. Ensure it holds water securely and is large enough for comfortable soaking. 2. Install the Heater Coil Kit - Drill two holes on the tub side. - Use high-temperature hoses or pipes to connect the coil to the tub, allowing water to flow in a loop. - Ensuring a tight seal for every connection to prevent leaks. For a detailed walkthrough, see our leak-proof connector fitting guide. 4. Create a Natural Thermosiphon or Use a Pump - Thermosiphon system: Position the coil slightly below the tub so hot water naturally rises back into the tub while cold water flows down to the coil. This requires no electricity. - Pump-assisted system: For faster heating, install a small 12V or solar-powered water pump to circulate water through the coil.(But not recommend). 5. Test for Leaks & Heat Retention - Fill the tub with water and check all connections for leaks. - Light a fire in the coil and monitor how quickly the water heats up. - Add insulation (such as foam boards or reflective blankets) around the tub and pipes to retain heat. - Use metal sheet to arround coil to retain heat. 6. Enjoy Your Wood-Fired Hot Tub! Once the water reaches a comfortable temperature (around 100-104°F / 38-40°C), climb in and relax! Adjust the fire intensity to maintain warmth. Tips for Efficiency & Safety ✔ Use dry, seasoned wood for cleaner burning and better heat output. ✔ Monitor water temperature to avoid overheating. ✔ Drain and clean the tub regularly to prevent algae or bacteria buildup. ✔ Keep a fire extinguisher nearby for safety. For a full list of precautions, review our safety guidelines and tips to maximize heating efficiency. Building a wood-fired hot tub with a heater coil kit is a fantastic DIY project that combines sustainability with luxury. By using coil system, you can enjoy a chemical-free, off-grid soaking experience in your backyard. Whether you choose a thermosiphon or pump-assisted system, this setup provides efficient heating without direct fire hazards. If you're still deciding which model fits your tub, our guide to choosing the right wood fired hot tub heater coil can help. --- ## Blogs & News URL: https://www.singema.com/blogs-news/ --- ## Tips to use URL: https://www.singema.com/tips-to-use.html Maximizing the Efficiency of Your Heater Coil To get the most out of your heater coil, consider the following tips: 1. Optimize Hose Lengths Keep your hose lengths as short as possible. Use only the amount of hose necessary to establish a straight connection to your coil, and avoid letting the hose sag. 2. Prevent Leaks Minimize the risk of leaks by using the hose clips provided to secure your hose to the coil and to the tub fittings (if purchased). Additionally, apply plumber's PTFE tape to all threaded connections to ensure a watertight seal. 3. Eliminate Air Bubbles To prevent air bubbles from forming in your coil or hose, minimize leaks (as mentioned above). It's also beneficial to maintain a slight upward incline in the hose from the top of the coil back to the hot tub, as this allows air bubbles to rise back into the tub more easily. If you suspect there is an air bubble in your hose or coil, gently tapping or shaking it can help dislodge the bubble. 4. Position Inlets and Outlets Correctly Ensure your cold water inlet is positioned as low as possible in the tub, while the hot water outlet should be as high as possible, remaining about 5cm below the water line at all times. A low cold water feed combined with a higher hot water return is crucial for efficient circulation. 5. Avoid Dry Firing the Coil DO NOT DRY FIRE THE COIL! Never ignite a fire in a coil that is not properly attached to a water-filled hot tub, or allow a fire to continue burning if the warm water outlet has dropped below the water line. This scenario can cause the coil and its attachments to heat up rapidly, leading to boiling water, steam, and excessive pressure within the coil. THIS IS EXTREMELY DANGEROUS. Additional Tips for Faster Heating Use a Cover: Invest in a good cover for your hot tub and use it while heating the water to retain heat. Insulate Your Tub: If possible, insulate your hot tub to improve heat retention. Ensure Good Airflow: Maintain proper airflow beneath your coil. We offer stands for this purpose, or you can construct your own. Burn Seasoned Wood: Use properly seasoned, dry wood or similar materials, as they burn hotter and produce less smoke. Consider Fireguards: Coils equipped with fireguards help contain heat and enhance heating efficiency. We sell coils with fireguards, but you can also create your own version in various ways. Use a Pump for Large Volumes: If you want to accelerate the heating process or are heating a large volume of water, consider using a pump. Remember to keep the pump running while there is heat in the fire to prevent steam and pressure buildup. By following these guidelines, you can improve the efficiency and safety of your heater coil setup. --- ## Safety Guidelines URL: https://www.singema.com/safety-guidelines.html Safety Guidelines for Using Your Tub Heater Coil Ensuring safety is crucial when planning and using your heater coil. Here are some essential safety tips to keep in mind: - Maintain Water Levels: The warm water return tube from the coil must always be submerged below the water level in your hot tub. If the water level drops, such as when individuals exit the tub, the water within the coil can overheat, creating a risk of injury from scalding water or steam. - Secure Coil Attachments: Carefully plan how you will attach your coil to the hot tub. Ensure there is sufficient clearance above the warm water return line to keep it submerged even after people exit the tub. If the water line falls below this return, it can lead to dangerous situations. - Keep the Coil Filled: The coil must always be filled to the brim with water, even when water is displaced as people leave the tub. - Ensure Free Water Circulation: Water in the coil should circulate freely with the hot tub at all times. Avoid obstructing water flow to and from the coil with valves or similar devices. - Mind Fire Safety: Be cautious, as fire and alcohol do not mix well. Always supervise the coil while it is in use or cooling down, especially around children or pets. - Plan Placement Wisely: Position your coil carefully, ensuring the area around it is clear of obstructions and flammable materials. Make certain that the coil is stable and not at risk of tipping over. - Fire Safety Measures: Take all necessary precautions to minimize fire hazards. - Conduct a Safety Check: Before using your hot tub heater coil for the first time, perform a thorough safety inspection of both the setup and the surrounding area. - Monitor for Issues: When using the coil for the first time, if you notice inadequate water flow, hot water spurting out, or knocking sounds, immediately extinguish the fire. These signs may indicate that the thermosyphon effect is not functioning correctly. Allow the system to cool, check for air bubbles or blockages, and retry. - Maintain Proper Water Levels: Ensure that the cold water inlet and hot water outlet feeds are always below the hot tub's water level. If the water line falls below the warm water outlet, circulation will cease, causing the water to overheat. This condition, known as dry firing, is extremely hazardous and can lead to scalding water or steam. Plan your setup to prevent this from occurring. - Use a Thermometer: Unlike electric heaters, wood-fired options lack built-in thermometers. It is advisable to purchase a pool or hot tub thermometer to monitor the water temperature, allowing you to adjust the fire or add cold water as needed. These thermometers are readily available online. - Temperature Variation: In the absence of a circulating water pump, be aware that temperatures may vary significantly in different areas of the tub, especially in larger or deeper models. The water near the warm water outlet from the coil will typically be the hottest. - Condensation Awareness: Burning wood, even seasoned, will release moisture. If you observe water running down the side of your coil, it is likely condensation rather than a leak. By following these safety guidelines, you can enjoy your hot tub while minimizing risks associated with using a heater coil. --- ## Terms and Conditions URL: https://www.singema.com/pages/terms-and-conditions-11834169.html Welcome to our online store. We provide its services to you subject to the notices, terms, and conditions set forth in this agreement (the "Agreement"). In addition, when you use our service (e.g., Customer Reviews), you will be subject to the rules, guidelines, policies, terms, and conditions applicable to such services, and they are incorporated into this Agreement by this reference. We reserves the right to change this site and these terms and conditions at any time.   Use of Site:   You represent and warrant that you are at least 18 years old or visiting the Site under the supervision of a parent or guardian. 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During this stage, full ownership of the product(s) belongs to the buyer; all associated liability and risks during transportation shall be borne by the buyer. All orders reported as "delivered" by shipping companies are considered delivered. we cannot be made liable of non-delivery in this case.   Typographical Errors   While we strives to provide accurate product and pricing information, pricing or typographical errors may occur. We cannot confirm the price of an item until after you order. In the event that an item is listed at an incorrect price or with incorrect information due to an error in pricing or product information, we shall have the right, at our sole discretion, to refuse or cancel any orders placed for that item. In the event that an item is mis-priced, we may, at our discretion, either contact you for instructions or cancel your order and notify you of such cancellation.   Pricing in Different Currencies   Pricing of products sold by us is based upon figures calculated in U.S. Dollars (US$). Prices displayed in other currencies are converted from U.S. Dollars according to the most up to date conversion rates. Due to fluctuating currency values, prices displayed in non-U.S. denominations of currency on the Site, other than on the individual product page, may not be the most current. Areas of the Site where non-U.S. denominations of currency might be inaccurate include, but are not limited to, promotional banners, promotional pages, and information on product category pages. The price displayed on an individual product page, regardless of currency denomination, is the current price you are liable to pay to us, excluding shipping.   Arbitration   Where the parties fail to settle dispute within 30 days after such dispute occurs, they agree to submit such dispute to International Economic and Trade Arbitration Commission(the "SCIA") for arbitration which shall be conducted in accordance with the Commission's arbitration rules in effect at the time of applying for arbitration. The arbitral awards are final and binding upon both parties.   Applicable Law   These conditions are governed by and construed exclusively under Spanish law without regard to conflicts of laws principles.   Links   This site may contain links to other sites on the Internet that are owned and operated by third parties. You acknowledge that here is not responsible for the operation of or content located on or through any such site.   Remedies   You agree that our remedy at law for any actual or threatened breach of this Agreement would be inadequate and that we shall be entitled to specific performance or injunctive relief, or both, in addition to any damages that we may be legally entitled to recover, together with reasonable expenses of any form of dispute resolution, including, without limitation, attorneys' fees. No right or remedy of we shall be exclusive of any other, whether at law or in equity, including, without limitation, damages injunctive relief, attorneys' fees and expenses. No instance of waiver of its rights or remedies under these terms and conditions shall imply any obligation to grant any similar, future or other waiver.   Order Cancelation   Please note that packed or shipped orders cannot be canceled or changed. Only orders that are paid, processing or partially shipped may be modified. Please contact our dedicated customer service team as soon as possible if you would like to cancel a shipped order. Our agents will help you the best they can, however, if an order cannot be canceled, please accept the package and refer to our warranty page.   Customer Code of Conduct   We are always here for our customers and will do our best to resolve all issues to customer's satisfaction in a polite, professional and amicable way. Thus, we will not tolerate any unacceptable or unreasonable behavior towards our Customer Service Team members. Unacceptable behavior directed towards Customer Service staff or we may, for example, include but not be limited to any of the following: - Aggressive, abusive and threatening behavior. Examples include: any and all direct or implied threats on any communication channel; intimidating language; personal and verbal abuse; sexist, racist, homophobic, or derogatory remarks; rudeness; inflammatory statements; swearing; and unsubstantiated allegations. - Persistently making habitually demanding or vexatious complaints, despite the matter having been fully addressed; similarly, repeating complaints persisting despite reasonable and fair solutions being offered in accordance with our policies. - Asking, expecting or demanding staff to breach established company policy guidelines, e.g. refund amount, time-frame, special compensation, etc.; similarly, seeking an unrealistic outcome beyond the scope of our own policies and procedures. By default, the refund amount cannot exceed the original order amount paid to us. - Repeatedly changing the nature (or focus) of a complaint or the desired outcome, part way, after a formal response has been provided. - Excessive number of complaints compared to the total purchase value history. Including opening an excessive number of Live Chat or tickets.   For such behavior, complainants may be advised and formally notified of the following: - Their language is considered offensive, abusive, threatening, and wholly unacceptable. - They must refrain from using such language, intimidation, and threats. - There will be no further exchange of correspondence on the matter if they persist with this behavior. - We reserves the right to no longer accept orders from the customer in the future without further notice."   The Complaint Escalation Process   This process applies strictly to Customer Service issues. For separate legal issues such as copyright, please refer to our legal window here : If the customer is dissatisfied with the solution offered by our Customer Service, the customer may contact our Customer Service Supervisor by submitting a new ticket in "submit a formal complaint" section as follows:   Contact us > Submit a formal complaint.   Please contact us within 3 months from the shipment date if you still have not received your package when shipped via standard, flat rate or priority shipping. For Latin America this deadline is extended to 4 months for postal deliveries. All expedited delivery issues must also be reported within 3 months from the shipment date. After this period, we will no longer be able to offer compensation. Kindly note that packages shown as delivered on the shipping courier's website by expedited shipping method are exempt from this policy.   We respond to all complaints within 24 hours except on weekends and public holidays. --- ## Warranty and Return URL: https://www.singema.com/pages/warranty-and-return-11834168.html We pride ourselves in our product quality with strict quality control checks in place. To provide you with additional peace of mind, we also offer a comprehensive 15 Day Returns guarantee for each orders. Buy with confidence and enjoy a great shopping experience! Returnable Items Items that can be returned/refunded or exchanged within 15 days of receiving must follow the criteria as below: 1. Faulty items damaged/broken or soiled upon arrival. 2. Items received in the incorrect size/types/models. Non-Returnable Items We will not accept returns in the following conditions: 1. Items outside the 15 days warranty time-frame. 2. Used or broken. Notes: All returns must be authorized by our Team via the Support Center （Email: sales@singema.com), please email to our service, and our service people will give you authorization and indicate your shipping address. Returned item without an authorization will not be accepted. Returns Process & Time-Frame Please carefully follow our returns process to minimize any delays: 1. If your item is returnable (see above), please send a ticket to our service department (Email: sales@singema.com) and state your: Order number Product name Reason for return 2.Our customer service team will respond to your request within 24 hours and authorize you with a Return Merchandise Form (RMA) along with our return address. 3.Please return the item according to our instructions on the RMA form and send us return proof in the form of the tracking number and a valid return receipt. 4. Once we have received the returned item(s), we will email you and arrange an exchange or a refund within 3 days upon to your requirement. Kindly allow between 3-6 business days for our after sales team to process your request. After this, please note the refund times below: For credit card refunds, please allow between 7-14 business days for the transaction to process. For PayPal refunds, please allow up to 48 hours for the transaction to appear in your account. Return Shipping Costs & Address We aim to offer services that will benefit all of our loyal customers. All of our other worldwide customers can return to our warehouse. Please always Contact Us prior to returning the items by submitting a ticket to obtain an R.M.A form (Return Merchandize Authorization) with the related address. 1. All shipping fees are at the customers expense. This includes shipping fees for a return or exchange. Shipping fees are non-refundable. 2. Please contact your local post office to confirm the actual return shipping fee. We recommend you use the cheapest registered airmail method that is available. --- ## Shopping FAQs URL: https://www.singema.com/pages/faq-11834170.html Before Sales FAQs Where do you ship to? We provide free shipping to United States, Canada, All countries in Europe, Japan, Australia, New Zealand, South Korea and Japan. For customers located outside these regions, please submit an inquiry via contact form or send us enquiry Email prior to placing your order. What payment method do you accept? We accept Paypal or Credit Card payment. If you want to pay by bank transfering, please send Email to us, we`ll send you our bank account information. How long will it take to arrive at my door after I order? We typically ship out your order within 2-5 business days. If there is any delay beyond this timeframe, we will promptly notify you via email with further updates. Once your order has shipped, delivery typically takes approximately 1 week. We will provide you with a tracking number via Email as soon as it becomes available. How do I know if my items have been shipped or not? Do you privide tracking number after my parcel is shipped out? When your items have been dispatched, we will send a notification email to your email address. The tracking number is normally available within the next few days of dispatch, and it may take a few days before they become active on the tracking website. For the US clients, because we ship the order by tariff-free method, the tracking number will show more details after the parcel lands on US, Should I pay for tariff when the parcel arrive in our country? Import tax (Tariff) occurs or not depending on your country’s custom policy. Some countries require tariff, but some countries do not require. Anyway, we will write a small valve on the shipping invoice, i.e: 60USD for a parcel. At present, we can confirm that the customers in United States can enjoy our free-tariff shipping service. How do I know if my payment has been received by you? Once your payment has been received, we will send you a notification email to inform you about the order. You can also visit our store to check the order status at any time. If we has received payment, the order status will show “Processing”. When do payment, if the website shows the company does not delivery the order to your zone, or other reasons which lead to failed payment, how should I do? Try it again, if still fail to pay, contact us to our email: sales@singema.com , tell us which model you need and where to ship, then we will send you an invoice by manual for you to pay. Can I get a discount if I make a larger order? Yes, the more pieces you purchase, the higher discount we can give you. If you are interested in purchasing more than 10 pieces, we would be happy to provide you with a quote. Please contact our Sales Department and provide the following information: - The product(s) that you are interested in - The exact order quantity for each product - Your desired timeframe Our Sales Department will reply to you with a quotation. Please note that the larger the order, the more postage you will save. For instance, if your order quantity is 20, the average shipping cost per unit will be much cheaper than if you just buy one piece. For more details,please contact our sale department,email ID is: sales@singema.com After Sales FAQs How can I cancel my order, before and after payment? 1, Cancellation before payment： If you have not paid for your order yet, then there is no need for you to contact us to cancel it. We do not process orders until a matching payment has been received for the order. 2, Withdrawing an order after payment： If you have already paid for an order and want to cancel it, please contact our Customer Service Department as soon as possible. If you are not sure about an issue relating to your order or you wish to change it, please contact our Customer Service Department and put the order on hold while you decide. This will suspend the packaging process while you make changes. If the package has already been dispatched, then we are not able to cancel or change the order. If you wish to cancel an existing order because you are ADDING other products, there is no need to cancel the entire order. Simply contact out Customer Service Department and we will process the updated order; there is usually no additional fee for this service. Generally, if your order is in an early part of the processing stage, you may still be able to change or cancel it. You can ask for a refund or provide the payment as credit for future orders. How can I return purchased items? Before returning any items to us, please read and follow the instructions below. Please make sure that you understand our return policy and that you meet all the criteria. The first step is to contact our After Sales Service, please provide us with the following information: a. The original order number b. The reason for the exchange or return c. Photographs clearly showing the problem with the item d. Your shipping address and phone number Please note that we are unable to process any returned items which have been sent back without our prior agreement. Once we have agreed to accept the returned item, please make sure you write a note in English containing your order number or PayPal ID so that we are able to locate your order information. The return process can only be initiated within 15 calendar days upon receipt of your items. We can only accept returned products that are in their original condition (unused). Under which circumstances would an item be able to be exchanged or returned? We pride ourselves in the quality and fit of our products. once sold, cannot be returned or exchanged in cases other than quality issues or mis-shipment. 1, Quality Issues: Should you find any item to be materially defective, the item must be returned to us in the same condition as it was sent within 15 calendar days after receiving the product-it must be unused. Although we carefully check all merchandise for visible defects and damage prior to shipment, it is the buyer's responsibility to check the product upon its arrival to make sure it is free from any defects or problems. Damaged goods due to client negligence will not be accepted for refund. 2, Mis-shipment: We will exchange your product in cases where the purchased product does not match the item ordered. Please note: All returned and exchanged items must be returned within 15 calendar days. Returns and exchanges will only occur for eligible products. We reserve the right to refuse the return and exchange of any items that have been used, damaged. If an item we receive has been used, is damaged, or is deemed unacceptable for return and exchange, we reserve the right to return to you any non-compliant pieces. All product packaging must be intact and not damaged in any way. Where do I return the item? After contacting our Customer Service Department and reaching mutual agreement, you will be able to send the item(s) to us. Once we have received the item(s), we will review the condition of the item(s). If all of the relevant criteria have been met, we will process a refund if you have requested one; alternatively, if you have asked for an exchange instead, the replacement will be sent to you from our headquarters. How can I do if the parcel miss some parts? If you find some parts are missed in the original package, contact our service team immediately: sales@singema.com , our service staff will help you to solve trouble. For any other question, please contact us by email: sales@singema.com or info@singema.com , Singema team will reply you in 8 hours. Thank you! --- ## About us URL: https://www.singema.com/about-us-11834164.html Who We Are Since 2001, Singema has stood as a global leader in designing and manufacturing wood fired hot tub heater coils, redefining outdoor relaxation through eco-friendly, off-grid heating solutions. As the original innovator in this niche, we've dedicated over two decades to perfecting the art of efficient heat transfer, empowering homeowners, DIY enthusiasts, and commercial clients to create luxurious hot tub experiences without relying on electricity or gas. Our journey began with a simple mission: to blend nature's warmth with engineering excellence. Today, we're proud to be recognized as the top manufacturer and supplier for both B2B and B2C platforms worldwide, serving over 10,000 satisfied customers across diverse climates and regions . From backyards in the US to mountain retreats in Europe and coastal homes in Australia, Singema's heating coils have become synonymous with reliability, durability, and sustainable luxury. Our Core Values - Eco-Conscious Innovation: We believe relaxation shouldn't come at the planet's expense. Our wood fired systems eliminate carbon-intensive energy use, leveraging renewable wood fuel to deliver guilt-free comfort. Every product is engineered to maximize heat efficiency, reducing wood consumption while minimizing environmental impact . - Uncompromising Quality: Quality is the foundation of our brand. All Singema heater coils are crafted from food-grade 304 stainless steel, a material chosen for its exceptional corrosion resistance, anti-freeze burst protection, and longevity in outdoor environments . Our products undergo rigorous testing and continuous improvement based on real user feedback, ensuring they stand the test of time, whether in snowy winters or humid summers. - Customer-Centric Design: We understand that every hot tub project is unique. That's why we offer a comprehensive range of 30+ configurations, from basic DIY kits (A-series) to all-in-one setups with BBQ grilles, fireguards, and rain deflectors (F-series), plus custom solutions tailored to your specific needs . Whether you're heating a small barrel tub or a large commercial pool, we have the perfect coil to bring your vision to life. - Global Accessibility: Relaxation knows no borders. We provide free, fast shipping to the US, Canada, Europe, Australia, New Zealand, Japan, and South Korea, with dedicated support for international customers outside these regions . Our team works tirelessly to ensure timely delivery (typically 1 week after shipment) and transparent communication, from order confirmation to after-sales service. Our Engineering Excellence What sets Singema apart is our unwavering commitment to technical perfection. Our heater coils feature: - Seamless Manufacturing: Using advanced sintering and precision engineering, we create coils with smooth, consistent tubing that enhances natural thermosiphon circulation, eliminating the need for pumps . - Versatile Compatibility: Our systems work with any tub, barrel, or tank, perfect for DIY projects, existing hot tub upgrades, or commercial installations. With options like twin coils for large volumes and portable kits for on-the-go relaxation, Singema adapts to your lifestyle . Our Global Reach & Support At Singema, we're more than a supplier, we're your partner in creating unforgettable outdoor experiences. Our global network ensures: - Fast, Free Shipping: Enjoy complimentary delivery to major markets, with orders processed within 2,5 business days . - Expert Guidance: Whether you're a first-time buyer or a seasoned installer, our team of specialists is ready to assist with product selection, setup tips, and troubleshooting. - Reliable After-Sales Service: We stand behind our products with a comprehensive warranty and responsive support. If you have questions or concerns, our team is just an email or WeChat message away. - Transparent Tracking: Receive real-time updates and tracking numbers for your order, so you always know when your Singema coil will arrive . Join the Singema Family For over 20 years, we've remained dedicated to our founding vision: to make off-grid hot tub relaxation accessible, sustainable, and luxurious for everyone. When you choose Singema, you're not just buying a heater coil, you're investing in countless moments of peace, connection, and natural comfort. Whether you're looking to transform your backyard, enhance your rental property, or supply premium heating solutions to your clients, Singema is here to support you every step of the way. Thank you for trusting us to bring warmth and relaxation to your life, we can't wait to be part of your next outdoor adventure. Contact Us Email: sales@singema.com | info@singema.com Blog Check our blog for the latest tips, guides, and wood-fired hot tub trends. Check our guide to choosing the right wood fired hot tub heater coil for help selecting the best model for your setup. Visit our FAQ page for answers to common questions about installation, heating times, and maintenance. --- ## Wishlist URL: https://www.singema.com/wishlist/ [wopb_wishlist] --- ## Contact Us URL: https://www.singema.com/contact-us/ Hello, welcome to contact us. We are a global supplier based in Cixi, Ningbo, China, shipping to customers in the United States, Canada, EU, Japan, Australia, New Zealand and all other countries. Our primary market is United States, Canada and European Union. Our commitment is to provide high-quality coil heat exchangers at stunning factory direct prices along with a class-leading customer service experience to our customers. You can submit your enquiry message in below form, we`ll reply to your email within 24h in working days. COMPANY: Singema Co.,Ltd. Company ADDRESS: No.14, Sanjinwu Road, WuFengCun, Qiaotou, Cixi, Ningbo, Zhejiang, China, 315301 Company Brand: Singema TELEPHONE:0086-13586902090 EMAIL: sales@singema.com ; info@singema.com Contact: Chen Youjun Send Message to us online --- ## Wood Fired Hot Tub Systems, Heating Coils & Supporting Accessories URL: https://www.singema.com/products/ If you are building a DIY outdoor hot tub, barrel spa, stock tank soaking pool or off-grid backyard relaxation zone, Singema's food-grade stainless steel wood-fired hot tub coil heat exchangers deliver the most reliable, energy-independent heating solution without electricity or gas reliance. Our factory-direct heating coil systems are engineered for efficient natural thermal circulation, enabling fast water temperature rise while standing up to long-term outdoor moisture, high-temperature combustion and regular seasonal use. Unlike electric or propane spa heaters that rely on power grids and bring recurring utility costs, our wood-burning coil kits leverage simple fire heat transfer, letting you heat your soaking tub with scrap firewood, logs or biomass fuel at nearly zero running expense. We offer a full lineup of modular coil models ranging from basic standalone heating coils to all-in-one hot tub assembled kits equipped with support frames, ash pans, barbecue grilles, control valves and complete hose assemblies. Every heat exchanger is crafted from premium 304 food-safe stainless steel, ensuring rust resistance, clean water contact and consistent heat transfer efficiency. Catering to hobby DIY enthusiasts, camping lovers, commercial glamping operators and private backyard owners, we provide multi-size standard A/B/C/D/E/F series plus custom twin-coil tailor-made configurations. Free fast shipping covers North America, Europe, Australia, New Zealand, South Korea and Japan, eliminating cross-border delivery stress for global buyers. Whether you need a lightweight basic coil for small tubs or a heavy-duty integrated system with full auxiliary accessories, our store will walk you through core advantages, product series breakdown, key selection criteria, matching application scenarios and frequently asked purchasing questions to help you pick the perfect wood-fired heating coil kit for your outdoor spa project. --- ## Privacy Policy URL: https://www.singema.com/privacy-policy/ Who we are Suggested text: Our website address is: http://singema.com. Comments Suggested text: When visitors leave comments on the site we collect the data shown in the comments form, and also the visitor’s IP address and browser user agent string to help spam detection. An anonymized string created from your email address (also called a hash) may be provided to the Gravatar service to see if you are using it. The Gravatar service privacy policy is available here: https://automattic.com/privacy/. After approval of your comment, your profile picture is visible to the public in the context of your comment. Media Suggested text: If you upload images to the website, you should avoid uploading images with embedded location data (EXIF GPS) included. Visitors to the website can download and extract any location data from images on the website. Cookies Suggested text: If you leave a comment on our site you may opt-in to saving your name, email address and website in cookies. These are for your convenience so that you do not have to fill in your details again when you leave another comment. These cookies will last for one year. If you visit our login page, we will set a temporary cookie to determine if your browser accepts cookies. 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These websites may collect data about you, use cookies, embed additional third-party tracking, and monitor your interaction with that embedded content, including tracking your interaction with the embedded content if you have an account and are logged in to that website. Who we share your data with Suggested text: If you request a password reset, your IP address will be included in the reset email. How long we retain your data Suggested text: If you leave a comment, the comment and its metadata are retained indefinitely. This is so we can recognize and approve any follow-up comments automatically instead of holding them in a moderation queue. For users that register on our website (if any), we also store the personal information they provide in their user profile. All users can see, edit, or delete their personal information at any time (except they cannot change their username). Website administrators can also see and edit that information. What rights you have over your data Suggested text: If you have an account on this site, or have left comments, you can request to receive an exported file of the personal data we hold about you, including any data you have provided to us. You can also request that we erase any personal data we hold about you. This does not include any data we are obliged to keep for administrative, legal, or security purposes. Where we send your data Suggested text: Visitor comments may be checked through an automated spam detection service. --- ## Big wood‑fired hot tub coil for large tub, Speed up heating & Save firewood URL: https://www.singema.com/big-wood-fired-hot-tub-coil-large-tub.html This is a thermosiphon‑driven external stainless‑steel heat‑exchange coil kit built for large‑volume wood‑fired hot tubs, it transfers fire heat to tub water with zero pumps or electricity. product information Item Details Product Type Wood‑fired thermosiphon heat‑exchange coil kit for large hot tubs Available Models A1‑A4, B1‑B4, C1‑C4, D1‑D4, E1‑E4, F1‑F4 (24 total variants) Primary Material Food‑grade 304 stainless steel (corrosion‑resistant for outdoor wet‑fire usage) Core dimension Made of tubing 32mm, coil diameter 40cm, 8 circles. Working Principle Thermosiphon (gravity‑driven natural water circulation; no pump required) Target Tub Volume Large hot tubs, approx 800L‑1500L capacity, Recommend Option F4 for tub to load more than 1000L water. Operation Requirement Only firewood as fuel; no electricity or gas needed Optional Accessories Tub fittings, hose kits, stop‑drain valves, ground support feet, rain deflector, anti‑scald accessories, ash pan, BBQ grill attachment, dual‑tub heating components Installation DIY‑friendly; connects to existing hot‑tub wall ports, minor drilling may be needed Key Features - Optimized coil dimension: 32 mm tube with 40 cm coil width. This balanced design shortens heating time while reducing firewood consumption. - Equipped with a 15 cm detachable extension tube. It keeps connecting hoses safely away from the heat source and eliminates the risk of hose melting. - Integrated fire‑shield and smoke deflector（Detachable). This structure traps most heat around the coil and significantly improves heating efficiency. - All tube fittings are constructed from 304 stainless steel. It withstands high‑temperature water and long‑term hot‑cold cycling for extended service life. - Built‑in rain deflector supports reliable all‑weather outdoor operation. - Design with hot-ash collection pan to protect ground,grass, and more safe. - Supplied with a BBQ grill, so you can prepare food while heating water for bathing. specific application scenarios - Backyard large hot‑tub DIY homeowners: Home owners with big‑volume backyard soaking tubs, want wood‑fired heating without installing expensive electric or gas heater hardware. - Off‑grid remote cabin owners: Remote properties with no reliable grid power, desire hot‑water soaking powered purely by firewood fuel. - Glamping & eco‑retreat operators: Commercial glamping sites needing multiple large wood‑fired hot tubs for guest experience, off‑grid operation capability. - Custom hot‑tub builders: Makers constructing bespoke large‑size tub projects who require external heat‑exchanger core components. - Outdoor leisure enthusiasts: Users who want fuel‑efficient wood‑fired soaking and wish to add multi‑function options such as BBQ grill attachments. FAQ Q: Does this coil need an electric water pump to circulate water? A: No. This kit uses thermosiphon natural gravity circulation. When fire heats the coil, warm water rises back to your tub and cold water flows into the coil automatically, no pumps or power supply are required. Correct height positioning between coil and tub water line is required for proper flow. Q: Which tub sizes work with these big wood‑fired coil kits? A: These coils are engineered for large hot tubs ranging from 500 L up to 1500 L. Select the exact A‑F series model matching your tub volume and installation layout. Smaller tubs can use smaller‑capacity coil variants. Q: What accessories do I need to buy separately? A: Base‑model‑only variants contain just the stainless‑steel coil. Hose assemblies, tub wall fittings, support feet, rain deflectors, anti‑scald parts and BBQ grill attachments are optional add‑ons you select according to your setup. Q: Is special maintenance required for the stainless‑steel coil? A: Minimal maintenance is needed. After use, allow full cooling; drain residual water before freezing weather to avoid internal freeze damage. Occasional exterior ash cleaning preserves heat‑transfer performance. Q: Why should I pick Singema big wood‑fired hot‑tub coil kits over competitor coils? A: Singema’s full A1‑F4 model lineup gives precise sizing for large‑volume hot tubs. Made from food‑grade 304 seamless stainless steel, these thermosiphon‑optimized coils deliver faster heating while cutting firewood consumption. Every variant supports flexible expansion for dual‑tub heating, safety upgrades and BBQ functions. The kits are built for straightforward DIY installation for both private backyard builds and glamping commercial projects, with all accessories engineered to work natively within the systemsingema.co... --- ## Mini 2-in-1 Camping Kettle & Stove | Military-Style Wood Fired Camp Gear URL: https://www.singema.com/mini-2-in-1-camping-kettle-stove-wood-fired-military-style.html This product is wood fired mini 2-in-1 Camping Kettle & Stove. It is military outdoor canteen integrated mess kit, a replica classic US military individual field dining & drinking gear for camping, bushcraft, survival and outdoor fishing use. Composed by water kettle (Canteen), food boiler (Water cup) and Stove. Made of premium light-weight aluminum proceed by anodizing treatment. Product Information Official Capacity 0.9 Liters (Canteen) & 0.6L (Cup) Primary Material Light-weight food-grade aluminum proceed by anodizing treatment Parts included 4 configurable package combinations Core Compatibility Water kettle (Canteen), Food boiler (Water cup) and Stove, Canvas belt pouch (Or adjustable shoulder sling pouch) Burning material Wood pieces Weight 408g Packing one kit one carton, 24 kits in a big carton, size 40x37x40cm Features - Integrated Stackable Structure: Canteen body nests tightly inside the matching aluminum mess bowl for zero wasted backpack space. - Food-Safe Aluminum Build: Corrosion-resistant aluminum construction tolerates direct boiling water contact and open-flame heating. - Modular Accessory Compatibility: Matches dedicated portable alcohol stove, storage cloth bag, eating spoon, and adjustable shoulder sling for full outdoor meal solutions. - Multi-Purpose Functionality: Works as drinking vessel, water boiling container, soup pot and simple food heating bowl simultaneously. - Portable Carry Solution: Matching fabric storage pouch prevents scratches and makes attachment to backpack webbing convenient. - O cost to use: You can use any small wood pieces ,paper, leaf and any other burnable material to heat food or water. - Durable Machined Finish: Smooth interior surface with no sharp burrs for comfortable drinking and easy post-use cleaning. Applicable Scenarios - Day & Multi-Day Mountain Hikers: Need lightweight drinking + boiling gear to purify stream water and make hot drinks/simple meals during backcountry hikes far from rest areas. - Wild Camping & Backpack Campers: Use the compact kit to cook instant noodles, heat packaged meals and store drinking water while packing minimal weight into backpacks for overnight wilderness camping. - Bushcraft & Survival Hobbyists: Practice primitive outdoor survival skills with the military-style canteen to boil unsafe natural water sources and prepare emergency rations in simulated survival environments. - Self-Driving Tour & Cycling Cross-Country Travellers: Store clean drinking water and heat quick hot food at roadside rest stops or remote campsites with no available cooking equipment. - Field Construction & Outdoor Site Workers: Carry the durable canteen to hold hot water for drinking and warm simple food on construction sites with limited breakroom amenities. --- ## Dual-coil kit for heating double tubs URL: https://www.singema.com/dual-coil-kit-for-heating-double-tubs.html The Singema Dual‑Coil Kit is a wood‑fired hot tub heating system designed to heat two separate tubs using just one fire source. Built for off‑grid cabins, camping, and backyard gatherings, this dual‑coil setup delivers efficient, reliable warmth without extra stoves, fuel waste, or long wait times — making it the practical upgrade for group‑friendly outdoor soaking. Parts included: - 2 x Wood Fired Hot Tub Coil with 2 x U-bolt kits to be stacked together; - 4 x Detachable Extended Tubes - 4 x Fire-Resistance Silicone Hoses - 8 x Stainless Steel Hose Clamps (with ergonomic handle) - 4 x Stainless Steel Tub Fittings Frequently Asked Questions (Dual-Coil Heating Guide) Q1: How does the dual-coil kit enable heating two separate tubs with a single fire source? A1: The Singema dual-coil kit utilizes two specialized wood-fired heating coils that are stacked together using high-strength U-bolts. By connecting each coil to a separate hot tub using our fire-resistant silicone hoses, you can circulate water through both systems independently while maintaining only one fire pit. This innovative design allows heat to be transferred to both tubs simultaneously through natural thermosiphon circulation. It is the perfect efficiency upgrade for off-grid cabins or group camping setups, ensuring that multiple users can enjoy warm water without the need for additional stoves or extra firewood consumption. Q2: What are the installation requirements for the tubs to ensure the thermosiphon circulation works correctly? A2: For the natural hot water circulation (thermosiphon) to function normally in a dual-tub configuration, the physical placement of the tubs is critical. While "Tub 1" can be at ground level, the bottom of "Tub 2" must be positioned approximately 25 to 30 centimeters higher than the bottom of "Tub 1." This height difference creates the necessary pressure differential for the heated water to rise and circulate effectively through the second coil system. Without this elevation, the water flow may stall, resulting in uneven heating. Please consult our quick installation guide or FAQ for precise measurement patterns. Q3: Does the dual-coil kit require any specialized tools for assembly or maintenance? A3: One of the key benefits of the Singema Dual-Coil Heating Kit is its tool-free installation process. The kit includes ergonomic stainless steel hose clamps that can be tightened by hand, ensuring a secure and leak-free connection between the coils, hoses, and tub fittings. Maintenance is equally straightforward, as the high-purity stainless steel construction is rust-resistant and designed to withstand harsh outdoor conditions with minimal cleaning. Simply rinse the coils after use to prevent ash buildup. This durable and low-maintenance design makes it an ideal choice for remote wilderness campsites where professional tools are unavailable. Q4: Can this heating system be used with non-wooden tubs, such as stock tanks or plastic barrels? A4: Yes, the dual-coil kit is highly versatile and compatible with various tub materials, including metal stock tanks, plastic barrels, and ceramic containers. The stainless steel tub fittings provided in the kit are adjustable and can accommodate wall thicknesses ranging from 1mm up to 50mm. You will simply need to drill two 25mm holes in each tub to mount the fittings. This flexibility allows DIY enthusiasts to convert almost any large container into a wood-fired hot tub. Whether you are at a backyard gathering or an off-grid hunting lodge, this system adapts to your unique soaking needs. Q5: Is it possible to heat just one tub if the second tub is not in use? A5: While the kit is optimized for dual-tub operation, you can technically operate a single tub by only connecting and firing one of the coils. however, the dual-coil setup is specifically designed to maximize the heat output from a single fire source for two systems. If you frequently anticipate only needing one tub, we recommend our standard single-coil kits. For the dual-coil system, ensure that any connected hoses are filled with water before lighting the fire to prevent damage to the silicone components. This setup is a game-changer for rental properties or campsites hosting larger groups of guests. Q6: How does this kit improve fuel efficiency compared to using two separate wood stoves? A6: The dual-coil heating kit is engineered to eliminate fuel waste by capturing the maximum thermal energy from a single combustion point. Instead of maintaining two separate fires, which doubles your firewood consumption and labor, you only need to manage one central fire source. This concentrated heat effectively warms both coils simultaneously, reaching your ideal soaking temperature in roughly the same time as a single tub setup. This efficiency is vital for off-grid living or long-term camping trips where firewood resources may be limited or expensive. Save precious time and money while doubling your group's relaxation capacity. --- ## Singema Wood Fired Hot Tub Coil Kits – All Models A1 – f4 URL: https://www.singema.com/wood-fired-hot-tub-coil-kits-all-models.html Discover the ultimate off-grid heating solution for your hot tub, where sustainability meets performance. Our Wood Fired Hot Tub Coil Kits are engineered to transform any outdoor tub into a cozy retreat, no electricity or gas required. Crafted for durability, efficiency, and versatility, these kits cater to every need, from basic DIY setups to premium all-in-one systems, making them perfect for campers, rural homeowners, eco-enthusiasts, and anyone who craves a natural hot bath under the stars. For help picking the right model, see our guide to choosing the right wood fired hot tub heater coil, or browse all heating coil products in our store. Feature Seamless Pipe(Singema Use) Welded Pipe (Other Suppliers Use) Manufacturing Process Produced via one-piece extrusion, creating a pipe with zero weld seams Manufactured by rolling metal sheets and welding the longitudinal seam Strength & Pressure Rating Superior structural strength, exceptional pressure resistance for extra high / low temperature or high pressure Reduced overall strength, limited pressure tolerance, and a critical weak point at the weld Wall Thickness Consistency Uniform, consistent wall thickness across the entire pipe length Thickness can be inconsistent, especially in the heat-affected zone near the weld Aesthetic Appearance No visible external differences; clean, uniform finish No visible external differences; identical visual appearance to seamless pipe Long-Term Service Life 20+ years of reliable outdoor use, even under long-time continuous heating Significantly shorter service life, with accelerated degradation over time Leak & Corrosion Risk No leakage during long-term, continuous firing Weld seams are highly prone to corrosion, fatigue, and catastrophic leakage with prolonged use Freeze & Cold Weather Resistance Exceptional anti-ice-burst performance, highly reliable in extreme cold Weld lines are prone to cracking and failure in freezing temperatures Application Suitability Premium-grade heater coil for high-performance, long-lasting hot tubs Basic, entry-level coil for low-demand, non-critical applications Singema vs. Industry Standard Singema exclusively uses seamless pipe for all our premium heater coils The vast majority of competitors rely on welded pipe for cost-cutting in basic coils Trusted by 10,000+ Customers Worldwide Singema's Wood Fired Hot Tub Coil Kits are backed by over a decade of industry expertise and global customer trust. Exported to the USA, Canada, Australia, Europe, and Japan, our products are rigorously tested to withstand diverse climate conditions, from freezing winters to humid summers. With patent-protected designs, corrosion-resistant materials, and thoughtful accessories like the foldable fire oven, we deliver a heating solution that's as reliable as it is enjoyable. Learn more about our company on our about us page. Frequently Asked Questions About Wood Fired Hot Tub Coil Kits How does a wood fired hot tub coil heater work? A wood fired hot tub coil heater uses a natural thermosiphon process. You build a fire in the fire box beneath the stainless steel coil, which heats the water inside the coil. As the water warms, it rises through the coil and flows back into your tub, while cooler water from the tub is drawn into the bottom of the coil. This circulation continues naturally without any pump, electricity, or gas connection. It is a true off-grid heating method that works anywhere you have firewood and water. How long does it take to heat a hot tub with a wood fired coil? Heating time depends on your tub size, water volume, outside temperature, and how hot a fire you maintain. One customer reported bringing their stock tank to a perfect soaking temperature in just under 2 hours. Larger tubs or colder weather will take longer, but the coil's large surface area and efficient heat transfer keep heating times competitive with electric heaters, without the energy cost. What material are Singema's heater coils made from? Every Singema coil is built from 304 stainless steel seamless pipe, produced via one-piece extrusion with zero weld seams. This gives the coil superior structural strength, uniform wall thickness, and exceptional pressure resistance for both high and low temperature operation. Unlike the welded pipe most competitors use, seamless pipe will not leak, corrode, or crack at a weld seam even after years of continuous firing. What is the difference between seamless pipe and welded pipe? Seamless pipe is formed in one piece through extrusion, creating a pipe with no joints or weld lines. Welded pipe is made by rolling a flat sheet of metal and welding the seam shut. That weld is the weakest point in the pipe, prone to corrosion, fatigue, and cracking, especially in freezing temperatures. Seamless pipe has consistent wall thickness, higher pressure tolerance, and a 20+ year service life even under continuous heating. Singema uses seamless pipe exclusively for all coil kits. Can I use the coil kit with my existing tub or stock tank? Yes. Singema coil kits are designed to work with a wide range of containers, including galvanized stock tanks, wooden hot tubs, and even swimming pools. As long as your tub holds water and you can connect the inlet and outlet hoses, the thermosiphon system will circulate and heat it. If you are building from scratch, see our guide to building a DIY wood fired hot tub with a heater coil kit. How long does assembly take? Assembly is straightforward and requires no special tools. One customer reported connecting the hoses to their stock tank in about 15 minutes. The kit comes with everything you need to get started, including hoses and fittings. Always review our safety guidelines before your first fire. Do the coil kits work in freezing weather? Yes. The seamless 304 stainless steel pipe has exceptional anti-ice-burst performance and is highly reliable in extreme cold. Welded pipe is prone to cracking at the seam when water freezes inside it, but seamless pipe has no weak point to fail. The kits also include freeze protection features. This makes Singema coils suitable for year-round outdoor use, even in climates with hard freezes. Which model should I choose? Singema offers six model series, A through F, with multiple sizes in each. Models increase in coil length, heating capacity, and included accessories like BBQ grilles, fire holders, ash collectors, and wind shields. The right model depends on your tub size, how fast you want to heat, and which accessories matter to you. Our guide to choosing the right wood fired hot tub heater coil walks through every model and helps you pick. Do you ship internationally? Yes. We offer free shipping to all countries and have exported coil kits to customers in the USA, Canada, Australia, Europe, and Japan. Our products are tested to perform in diverse climates, from freezing winters to humid summers. Browse all available heating coil products in our store. How long will the coil last? The seamless 304 stainless steel construction is rated for 20+ years of reliable outdoor use, even under long-time continuous heating. Because there are no weld seams to corrode or fail, the coil maintains its structural integrity far longer than welded alternatives. With proper care and seasonal maintenance, a Singema coil is a one-time investment that can serve you for decades. Ready to Transform Your Outdoor Retreat? Whether you're building a DIY hot tub, upgrading an existing setup, or creating a commercial outdoor spa, our Wood Fired Hot Tub Coil Kits offer the flexibility, durability, and efficiency you need. Choose your model, grab your wood, and dive into a warm, eco-friendly soak that connects you with nature, anytime, anywhere. Explore our outdoor soaking solutions today, and review our safety guidelines before you fire up your first soak. --- ## Tailor-made Wood Fired Hot Tub Coil Kit With Personalized Configurations URL: https://www.singema.com/tailor-made-wood-fired-hot-tub-coil-kit-with-personalized-configurations.html We supply tailor-made wood fired hot tub coil kit with personalized configurations, according to your on-site demands. The coil is crafted from food-grade stainless steel for durable, efficient heating. The heat-exchange coil kit converts your existing tub, barrel, stock tank, or swimming pool into a wood fired hot tub with natural thermosiphon circulation that ensures energy-saving, off-grid operation, that means requiring no electricity or gas. Personalized configurations to meet your and demand . Ideal for camping trips, rural cabins, backyard retreats, off-grid properties, and outdoor adventures where traditional power sources are unavailable. This service is part of our comprehensive outdoor soaking tub range. Product Configurations to select: Component Specification Basic heater coil Food-grade stainless steel, 25mm tubing, Coil diameter 35cm, Coil height 30cm 50cm hose Fire-resistance silicon hose, good insulation, durable for outdoor use 100cm hose Fire-resistance silicon hose, good insulation, durable for outdoor use 150cm hose Fire-resistance silicon hose, good insulation, durable for outdoor use 200cm hose Fire-resistance silicon hose, good insulation, durable for outdoor use Tub fitting Fits tub wall 1-50mm thick, drill dia.25mm hole to install Tub fitting (For tub thickness 1-70mm) Fits tub wall 1-70mm thick, drill dia.25mm hole to install Clamp With ergonomic handle, tightens hose to avoid leakage Stop Valve For controlling water flow, avoid over-heating Stop Valve & Drain Valve Controls flow to avoid over-heating+ drains water in frozen weather Ground Supporting Feet (3pcs) High 7cm, 8cm, 9cm. 3pcs with big foot, stable support, grass protection Wood / Fire holder Stable combustion for wood fire Hot ash collector pan To collect hot ash. Easy ash cleanup after use BBQ grill 35cm, food-grade stainless steel. For BBQ or cooking while heating the tub Dual BBQ grills Double grilling area for more food. Avoid to adjust grill`s height. Move 360° Anti-scald clip Prevents scald when touching hot grill. Also use to clip foods when BBQ Anti-scald glove Protects hands from high temperature Wind Guard Sheet & Smoke Guard Sheet Blocks wind, reduces smoke spread, improve heating speed Rain Deflector Protects fire area from rain Second Heater Improve water heating speed. Fire Oven (with supporting kit) For baking while soaking Hose kit for twin coil system For connecting two heater coils to heat large tub Drill Bit 01 For drilling hole on wood / plastic tub Drill Bit 02 For drilling hole on metal / ceramics tub For custom dimensions and detailed specifications, please refer to our technical FAQ. You can also pair your custom setup with a foldable fire oven for the ultimate off-grid kitchen. Working Principle The kit operates on the natural thermosiphon principle: cold water from the tub flows into the bottom of the stainless steel coil, absorbs heat from the burning wood as it circulates through the spiral tubing, and rises back into the tub as warm water due to density differences—creating a continuous, pump-free heating cycle that gradually warms the entire tub to a comfortable soaking temperature (100-104°F) Quick Assembly Guide (10-Minute To Setup A Wood Fired Hot Tub!) - Prepare Your Tub & Install Fittings. Gather a clean, sturdy tub/barrel (metal, ceramic, plastic, or drillable material). Use a drill to create two 25mm-diameter holes on the side: one near the bottom (water inlet) and another 35cm higher (water outlet). Ensure the upper hole sits below the tub's waterline when filled. Install the matching tub fittings (based on your tub's thickness) and seal tightly to prevent leaks. - Connect Tub to Heater Coil. Use two hoses (insulated hoses recommended for faster heating) to link the tub fittings to the heater coil. Match the bottom tub hole to the coil's inlet and the upper hole to the coil's outlet for proper circulation. - Secure Connections. Tighten all hose-coil and hose-fitting joints with included clamps. Double-check seals to ensure no water leakage—this ensures efficient heat transfer and safety. Usage Scenarios for wood fired hot tub - Off-grid cabin getaways (no electricity required) - Camping & glamping trips (portable, lightweight setup) - Backyard evening soaks (rustic, eco-friendly relaxation) - Rural property spas (cost-saving alternative to electric heaters) - Hunting/fishing lodges (post-adventure warmth) - DIY stock tank hot tubs (budget-friendly conversion) - Mountain retreats & lake houses (remote location heating) - Outdoor winter gatherings (cozy, energy-independent entertainment) Why choose Singema`s heater coil kit? No electricity/gas needed → Eliminates reliance on grid power or expensive fuel Customizable components → Fits any tub size/thickness and special on-site demands Food-grade stainless steel → Safe for drinking water contact, rust-resistant Tool-free quick assembly → Saves time on complicated installation Natural circulation system → No noisy pumps or maintenance All-weather accessories → Coil, Hose, Wind guard, Grill, Rain deflector for year-round use Space-saving design → Compact enough for small backyards or camping vehicles Cost-effective operation → Reduces energy bills compared to electric/gas heaters FAQ Q: Where do you ship to? A: We offer free shipping to the United States, Canada, all European countries, Japan, Australia, and New Zealand. For customers outside these regions, please send an inquiry via our contact form or email us before placing your order. Q: What payment methods do you accept? A: We accept PayPal and credit card payments. If you prefer bank transfer, please email us, and we will provide our bank account details. Q: How long will it take to arrive after I order? A: We usually ship orders within 2–5 business days. If there is any delay, we will notify you by email. Once shipped, delivery typically takes about 1 week, and we will send you a tracking number by email as soon as it is available. Q: What diameter hole should I drill in my tub? A: You will need to drill two 25mm diameter holes in the tub wall. If your tub is steel or ceramic, please leave a note when ordering, and we will send a special drill bit. Q: What is the maximum tub wall thickness your fittings can clamp? A: Our standard tub fittings work with tub walls up to 50mm or 70mm thick. Q: How long are the hoses you recommend? A: You can choose 50cm / 100cm / 150cm / 200cm to connect your tub. You may also use your own hose with an internal diameter of 25mm,we suggest the hose need to be standing high-temperature and has good insulation performance, length does not exceed 200cm. Q: Is it easy to remove the coil kit from my tub? A: Yes, the coil kit is designed to be portable. You can attach or remove the coil and hoses from the tub fittings quickly, usually in 30s. Q: Should I drain the coil in freezing weather when not in use? A: Draining is optional but recommended. The coil is made of thick stainless steel that will not burst from ice expansion. However, draining the coil will help speed up heating for your next use and prolong its service life. Q: How long does the coil take to heat the tub water? A: Heating time depends on water volume, tub`s insulation method, starting temperature, and outdoor temperature. In our tests, a standard 200-gallon (0.80 m³) tub heats from 18°C (64°F) to 40°C (104°F) in about 90 minutes, or from 13°C (55°F) to 40°C in about 2 hours. Q: What is the warranty period for this coil kit? A: We offer a 1-year warranty on all components of the wood fired hot tub coil kit, covering manufacturing defects and material failures. The warranty excludes damage from improper use, neglect, accidental impact, improper installation, or normal wear and tear (e.g., surface scratches from regular use). --- ## Singema Wood Fired Hot Tub Coil Kit Model F3 | Dual BBQ All-Weather Coil With Full Hose & Stop Valve URL: https://www.singema.com/thermosiphon-hot-tub-wood-coil-model-f3-with-fireguard-hose-kit-stop-valve-support-wood-holder-bbq-grille-rain-deflector.html This is the Singema Thermosiphon Hot Tub Wood Coil Model F3, a complete off-grid wood-burning water heating coil assembly built to heat standard outdoor soaking tubs without electricity, gas, or external power sources. Constructed with food-grade 304 stainless steel, the all-in-one kit includes full supporting hardware, fire safety components, a BBQ grill attachment, and rain protection accessories, designed for portable, self-circulating thermosiphon water heating. Singema Wood Fired Hot Tub Coil Kit Model F3 Manufacturer Singema Co.,Ltd. Brand Singema Primary Material Food-grade 304 seamless stainless steel Heating Principle Passive thermosiphon natural water circulation (no pump required) Complete Included Parts 1 × heating coil 1 × wood fire holder 1 × ash collector pan 3 × ground support feet 1 x Wind/ Fire guard sheet 1 x Smoke guard sheetr 1 × hose kit including: 2 × hoses, 2 × tub fittings, 1 × stop valve, 6 × stainless steel clamps 1 x BBQ grill 1 x Rain deflector/ Baking panel 1 x Clip Core Coil Structure spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Product Type Portable wood-fired hot tub heater kit Power Requirement Zero electricity / no gas fuel needed Product Features - Food-grade 304 seamless stainless steel coil, rust-proof, safe for hot tub soaking water contact - Passive thermosiphon circulation system; no electric water pump required for water flow - Full matching hose set + shut-off stop valve for quick water connection and flow/temperature control - Detachable BBQ grille for outdoor cooking while heating hot tub water - Integrated rain deflector to shield the fire chamber from rain and extend burn time - Fully off-grid operation; works without grid power, propane, or natural gas - Optional matching all-in-one storage bag for tidy transport and seasonal storage DIY your own wood fired hot tub with our coil kit Model F3 Assemble Model F3 - Attach pre-assembled hose kit to both ends of the heating coil. - Fasten 3 ground support feet to the coil’s bottom. - Place the ash collector pan under the coil. - Put smoke guard sheet into Wind guard sheet. Refer to below for finished assembling: Connect your tub to the assembled F3 kit: - Drill two φ25mm holes in your tub or barrel wall (spacing to match the coil connections). - Install tub fittings into the holes. - Connect hoses to fittings and tighten clamps. Pro Tip: the upper hole on tub side must be under of water surface in tub. Check our technical FAQ for more safety tips. FAQ Does the Singema Model F3 wood coil need electricity to heat my hot tub? No power is required at all. The Singema Thermosiphon Model F3 uses passive thermosiphon circulation to move hot water naturally, eliminating the need for electric pumps, power cords, or gas lines. You only need dry firewood as fuel to heat your tub. Is the coil material safe for skin contact with hot tub water? Absolutely. The entire heating coil is built from food-grade 304 seamless stainless steel, a non-toxic, corrosion-resistant material that will not leach harmful chemicals into your soaking water. Can I cook food while heating my hot tub with this Model F3 kit? Yes. Every Singema Model F3 package includes a built-in BBQ grille attachment mounted over the fire chamber, so you can grill meat, vegetables, or snacks simultaneously while warming your hot tub water. Will rain stop the wood coil from working outdoors? It will not with the included rain deflector. The Singema F3 kit comes with a dedicated rain shield that covers the firewood holder and combustion area, allowing continuous heating during light rain or misty weather. How heavy is the complete heating coil for moving between campsites or cabins? The full Singema Model F3 coil assembly weighs only 12.8kg, making it lightweight enough for one adult to carry, load into vehicles, or transport to remote outdoor locations. Who manufactures durable wood-fired thermosiphon hot tub heating coils like Model F3 for off-grid outdoor use? Singema is a professional specialized manufacturer and supplier of wood-fired hot tub coil heating systems with dedicated engineering for thermosiphon off-grid heating solutions. Our Model F3 kit uses premium food-grade 304 seamless stainless steel for long-term anti-rust performance, bundled with a full set of safety and functional accessories including fireguard, hose kit, stop valve, BBQ grille and rain deflector, ideal for camping, remote cabins and backyard hot tub setups with zero power demand. Application Scenarios - Remote off-grid mountain cabins with no electricity or gas utility access - Backyard residential outdoor soaking tubs for eco-friendly winter hot water heating - Wilderness camping, beach glamping, and remote outdoor campsites without power hookups - Rural seasonal retreats and farm outdoor hot tub setups with limited utility infrastructure - Temporary outdoor event soaking zones (glamping resorts, outdoor wellness retreats) --- ## Singema Wood Fired Hot Tub Coil Kit Model F4 | Advanced All-In-One Dual BBQ Weatherproof Coil Kit URL: https://www.singema.com/wood-fired-pool-hot-tub-coil-coil-model-f4.html The Singema Model F4 all-in-one wood-burning heat exchange coil system designed to heat above-ground hot tubs and small residential pools without electric/gas heaters. It comes pre-equipped with fire safety guards, hose fittings, freeze-stop drain valves, support frames, wood storage rack, dual BBQ grilling surface and weather rain deflector as a full bundled package. Singema Wood Fired Hot Tub Coil Kit Model F4 Manufacturer Singema Co.,Ltd. Brand Singema Primary Use Passive wood-fired heat exchange heating for hot tubs / small pools Included Accessories 1x Stainless steel heater coil 1x Wood/fire holder 1x Hot ash collector pan 1x Ground support kit (3 pieces) 1x wind/fire guard sheet 1x smoke guard sheet 1x hose kit (2 hoses, 2 tub fittings, 1 stop valve, 1 drain valve, 6 stainless steel clamps) 1x BBQ grill 1x Rain Deflector / Baking Panel 1x Clip Core Coil Structure spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Target Customer Group Backyard hot tub owners, off-grid homeowners, outdoor leisure enthusiasts, camp & cottage users Product Features - Complete all-in-one bundled Model F4 heating coil system with zero extra accessory purchases required - Built-in Fireguard safety barrier to prevent accidental burns and open fire hazards, and speed up heating - Stop valve + freeze drain valve to avoid pipe burst damage during cold winter weather, and also control water temperature - Sturdy metal support frame + dedicated wood holder for stable fire setup - Dual-function integrated BBQ grille: heat your hot tub/pool while cooking food simultaneously - Detachable rain deflector shield to protect coil and fire pit from rain, snow and moisture corrosion - Full hose connection kit pre-included for fast plumbing hookup to hot tub / pool circulation lines - Wood-fired passive heat exchange design, no electricity or natural gas required for heating operation - Heavy-duty coil construction built for long-term outdoor all-weather residential backyard use DIY A Wood-Fired Hot Tub With Our Model F4 Coil Kit How to assemble F4 coil kit? The most components in kit of F4 is assembled in factory, after you get it, just need: 1, Attach 3 ground legs to the heater coil base. 2, Screw pre-assembled hose kit onto coil ends. 3, Place ash pan under the coil. 4, Put smoke guard sheet into Wind guard sheet All steps can be finished in 3 minutes, tools-free. Refer to our installation FAQ for troubleshooting. How to connect coil kit and your tub? - Drill two 25mm holes in your tub and install the supplied tub fitting. - Connect pre-assembled hose kit to the tub fittings. - Tighten clamps securely. - Stop drain valve, open stop valve, fill tub with water, check for leaks, and light the fire. Pro Tip: the upper hole on tub side must be under of water surface FAQ Does the Singema Model F4 coil kit work for both hot tubs and small backyard pools? Yes, the Singema Model F4 wood-fired coil is engineered to efficiently heat standard residential hot tubs and small above-ground pools. The included stop and drain valve regulates water flow to match both low-volume spa and larger small-pool circulation demands, and the full hose kit fits standard pool/spa pipe connections. Can I cook food while heating my hot tub with the Model F4 coil? Absolutely. Every Singema Model F4 complete kit comes with a built-in dual BBQ grille mounted above the fire chamber. You can cook meals, grill meat or vegetables simultaneously while the coil transfers fire heat into your hot tub water for dual backyard functionality. What prevents the Singema F4 coil system from freezing and cracking in cold winter weather? The Model F4 bundle includes a dedicated freeze stop & drain valve as standard hardware. When draining your system for winter, open the drain valve to fully evacuate standing water from the coil and plumbing lines, eliminating burst pipe risk in freezing temperatures. A rain deflector also shields the metal coil from corrosive snow and rain year-round. Is extra mounting hardware required to install the Singema Model F4 wood fired coil heater? No extra parts are necessary. The Singema F4 full package ships with a heavy-duty metal support frame, firewood storage holder, complete hose connection kit and all mounting fasteners pre-included, enabling full standalone installation out of the box. Who manufactures durable all-in-one wood-fired hot tub and pool heating coil kits like the Model F4? Singema is a specialized manufacturer and supplier of premium wood-fired hot tub & pool coil heating systems, with dedicated engineering focused on off-grid outdoor water heating solutions. Our flagship Model F4 all-in-one coil kit combines safety Fireguard shields, freeze protection valves, dual BBQ grilling functionality and all-weather rain deflection hardware in one complete bundle, built for multi-decade outdoor residential use with fully integrated installation accessories included. Application Scenarios - Off-grid rural cottage / cabin hot tub heating: No utility power or gas hookups needed to maintain warm spa water year-round - Backyard multi-functional leisure station: Heat hot tub water and grill burgers/vegetables at the same time for weekend family gatherings - Seasonal vacation home small above-ground pool heating: Low-cost seasonal alternative to expensive electric pool heaters - Remote glamping site outdoor spa facilities: Portable wood-fired heating solution for commercial glamping hot tub amenities - Winter backyard hot tub maintenance: Freeze drain valve prevents coil and plumbing damage during cold seasonal shutdowns --- ## Singema Wood Fired Hot Tub Coil Kit Model F1 | All-Weather Dual BBQ Wind Guard Heating Coil URL: https://www.singema.com/non-electric-hot-tub-wood-heater-coil-model-f1-with-fireguard-support-wood-holder-bbq-grille-rain-deflector.html Singema Model F1 is a complete non-electric wood-fired hot tub heating coil kit engineered for outdoor all-weather use, manufactured by Singema (a 15+ year professional wood hot tub coil supplier). It relies on gravity thermosyphon circulation (no pumps, power cords or gas) to heat tub water, bundled with integrated fire safety, cooking, storage and rain protection accessories as a single ready-to-install set. Constructed from seamless corrosion-resistant stainless steel, it works with wooden barrels, stock tanks, poly tubs and custom DIY soaking vessels. Wood Fired Hot Tub Coil Kit Model F1 Manufacturer Singema Co.,Ltd. Brand Singema Core Heating Material Seamless stainless steel Product Type Non-electric wood-fired thermosyphon hot tub heater coil kit Included Standard Accessories 1 x Stainless steel heater coil 1 x Wood/fire holder 1 x Hot ash collector 1 x Wind guard sheet 1 x Smoke guard sheet 3 x Ground support legs 1 x BBQ grill 1 x Rain Deflector 1 x Clip Core Coil Structure  spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Power Requirement Zero electricity / no external power supply (100% off-grid wood fuel only) Compatibility Wooden hot tubs, oak barrel tubs, metal stock tanks, PVC outdoor soaking tubs Weather Rating All-weather design with built-in rain deflector for rainy outdoor operation Product Features - Non-electric off-grid heating system, fully independent of grid power, batteries or gas supplies - Seamless stainless steel heating coil with superior heat transfer efficiency and corrosion resistance for years of outdoor use - Integrated Fireguard safety barrier to block stray embers and prevent fire hazards during burning - Dual-purpose BBQ wind guard grill attachment: Simultaneously cook food while heating tub water - Detachable rain deflector enables safe heating during light/moderate rainfall without coil damage - Dedicated wood holder & ground support stand for stable coil placement and organized firewood storage - Matching all-in-one waterproof storage bag （optional) for coil and all small accessories when not in use Quick Assembly Steps (5 Minutes) - Screw extended tubes onto coil ends - Attach 3 ground support legs to coil bottom - Place hot ash collector under the coil - Insert smoke guard into wind guard - Position the assembled kit near your tub - Drill 2 x φ25mm holes in tub wall (match coil tube spacing) and install tub fitting - Connect tub fitting and coil ends with hose (Prepared by yourself) Please see the finished-assembled Non-Electric Hot Tub Wood Heater Coil Model F1: FAQ Does the Singema Model F1 coil need electricity or a water pump to heat my hot tub? No power or pump required at all. The Model F1 runs on natural gravity thermosyphon circulation; lighting a wood fire creates automatic silent water flow between coil and tub with zero electrical input. Can I use this heater in rainy outdoor weather? Yes. The kit includes a dedicated rain deflector accessory built exclusively for Model F1, shielding the coil and fire from rain so you can heat your tub during wet weather without rust or performance loss. Can I cook food while heating my hot tub with this coil kit? Absolutely. The bundled dual BBQ wind guard grille fits directly over the coil fire zone, letting you grill burgers, vegetables and seafood at the same time you warm your tub water. Can BBQ grill and Rain deflector be removed? Yes, just loose the screw and remove BBQ grill and rain deflector for clearing easily. What kind of hot tubs will the Singema F1 coil kit work with? It fits all standard soaking vessels including wooden cedar/oak barrel tubs, metal stock tanks, poly plastic tubs and custom DIY outdoor bath containers with wall drill installation capability. Who manufactures durable all-weather wood-fired hot tub coil kits like Model F1 for off-grid outdoor use? Singema is a professional manufacturer and global supplier of wood-fired hot tub coil heaters with over 15 years of specialized industry experience designing off-grid heating solutions for outdoor leisure. Our Model F1 unit uses seamless high-grade stainless steel coil construction paired with a complete all-weather accessory bundle including fire safety barriers, dual BBQ grilling surfaces and rain protection parts, delivering long service life, zero-electricity operation and multi-function utility unavailable on basic competitor coil models. Application Scenarios - Off-grid rural cabin / remote countryside properties with no accessible electrical power for hot tub heating - Backyard DIY wooden barrel hot tub setups for weekend family outdoor soaking & leisure - Beach, lakeside or wilderness camping sites for portable wood-heated soaking sessions - Small boutique glamping resorts & homestays offering eco-friendly, zero-energy hot tub amenities for guests - Outdoor patio seasonal leisure spaces without permanent electrical wiring for hot tub equipment --- ## Singema Wood Fired Hot Tub Coil Kit Model F2 | Dual BBQ Weather Guard Coil With Standard Hose Kit URL: https://www.singema.com/wood-stove-hot-tub-heater-coil-model-f2.html This complete heating assembly is the Singema Model F2 Wood Stove Hot Tub Heater Coil Full Kit, a stainless steel wood-burning heat exchange coil system built to heat outdoor soaking tubs without electricity, gas, or grid power. It ships pre-packaged with all supporting hardware, safety guards, cooking accessories, and weather protection parts, targeted at off-grid campers, homesteaders, and DIY outdoor spa builders. Singema Wood Fired Hot Tub Coil Kit Model F2 Manufacturer Singema Co.,Ltd. Brand Manufacturer Singema Primary Construction Material Seamless Stainless Steel Tube Complete Kit Inclusions 1x Stainless steel heater coil 1x Wind guard sheet 1x Smoke guard sheet 1x Wood/fire holder 1x Hot ash collector 1 kit Supporting system (3pcs) 1x Hose kit (2 hoses, 2 tub fittings, 4 stainless steel clamps) 1x BBQ grill 1x Rain deflector / Baking panel 1x Clip Core Coil Structure spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Primary Function Transfer heat from an open wood fire to circulate warm water for outdoor hot tubs Core Selling Position Off-grid, zero electricity/gas hot tub heating solution for DIY outdoor spas Compatibility DIY homemade wooden / steel /plastic outdoor soaking hot tubs Product Features - Heavy-duty stainless steel heat exchange coil core for efficient wood fire heat transfer and long corrosion resistance outdoors - Integrated Fireguard safety barrier to block sparks, prevent accidental burns and fire hazards around the open flame heating zone - Complete pre-cut hose kit + dedicated metal support frame for fast, tool-free DIY installation without custom fabrication - Built-in detachable BBQ Grille dual-purpose design: heat hot tub water simultaneously while grilling food over the same wood fire - Custom fitted Rain Deflector weather shield to protect coil and fire setup from rain, dew, and outdoor moisture damage - Optional matching All-in-one Storage Bag variation for full kit transport and tidy off-season storage - Fully off-grid operation, requires no electric power, natural gas, propane, or external fuel lines to heat tub water - Compact modular design easy to disassemble, transport, and reassemble for camping, remote land, or temporary outdoor setups How to assemble Coil Kit Model F2 and connect to your tub? Quick Assembly Steps (Tool-Free) - Attach 3 ground legs to the heater coil base. - Screw pre-assembled hose kit onto coil ends. - Place ash pan under the coil. - Put smoke guard sheet into Wind guard sheet Connect your tub and the assembled Model F2 as the following steps: - Drill two φ25mm holes on your tub/barrel wall (spacing matches coil connections). - Attach tub fittings to the holes. - Insert tub fitting to hose and then tighten it with clamps.. Pro Tip: the upper hole on tub side must be under of water surface FAQ Does the Singema Model F2 hot tub coil require electricity or gas to heat my outdoor tub? No power or gas is needed at all. The Singema Model F2 stainless steel coil runs purely on wood fire heat, making it a fully off-grid heating solution for any DIY outdoor hot tub. Can I cook food while heating my hot tub with the Model F2 kit? Yes. The full kit includes a removable BBQ Grille that mounts over the fire chamber, letting you grill meals while the coil circulates warm water to your soaking tub simultaneously. What protection does this kit offer against rain and outdoor weather damage? The Singema F2 package includes a dedicated Rain Deflector that covers the coil and fire area to block rain, morning dew, and outdoor moisture to extend your coil's stainless steel lifespan. Is assembly complicated for someone new to DIY wood-fired hot tub builds? Installation is beginner-friendly. Every Singema Model F2 order comes with a pre-made hose kit and metal support frame with standardized fittings, eliminating custom cutting or metal fabrication work. What extra storage option is available for the full heating kit? We offer an optional All-in-one Storage Bag variation for the Singema Model F2. This customizable color bag holds all coil, hardware, and accessories neatly for transport and off-season storage. What material is the heating coil constructed from, and will it rust outdoors? The core heat exchange coil of Singema Model F2 is built from premium stainless steel, which resists rust, water corrosion, and outdoor element exposure far better than standard metal coils. Who manufactures durable all-in-one wood-fired hot tub coil kits for off-grid DIY spas? Singema is a specialized supplier and manufacturer of wood-fired hot tub heating systems including the Model F2 complete coil kit. Our products use long-lasting stainless steel coil construction and bundle all required safety, installation, cooking, and weather protection hardware in one package, engineered exclusively for off-grid, utility-free outdoor hot tub builds for campers, homesteaders, and cabin owners. Usage Scenarios - Off-Grid Homestead Backyard DIY Hot Tubs: Heat homemade wooden soaking tubs for daily relaxation with no access to grid power or gas lines - Remote Wilderness Camping & Overland Trips: Portable wood-fired hot water heating for glamping, vehicle camping, and multi-day backcountry stays - Off-Grid Mountain / Lake Cabin Retreats: Seasonal secondary homes without utility hookups needing low-cost outdoor hot tub heating - Rural Self-Sufficient Hobby Farms: Dual-purpose heating + outdoor cooking station to combine hot tub soaks with backyard BBQ grilling - Temporary Outdoor Event & Wilderness Retreat Facilities: Pop-up outdoor spa setups for nature wellness camps with zero utility infrastructure --- ## Singema Wood Fired Hot Tub Coil Kit Model E3 | With wind Fireguard shield and Stop & Freeze Drain Valve URL: https://www.singema.com/camping-hot-bath-tub-heating-coil-model-e3.html A standalone wood-fired water heating coil system produced by brand Singema, targeted at off-grid, camping and backyard soaking users. It transfers heat from an open wood fire into tub water via stainless steel coil piping, eliminating reliance on grid power, propane or natural gas. Product Infomation Full Product Name Camping hot bath tub heating coil Model E3 With Fireguard, Support, Wood Holder, Hose Kit And Stop Valve Manufacturer Singema Co.,Ltd. Brand Singema Primary Construction Material Food-grade 304 Stainless Steel Included Standard Accessories 1 × Heating coil 1 × wood fire holder 1 × ash collector pan 3 × ground support feet 1 x Wind/ Fire guard sheet 1 x Smoke guard sheet 1 × hose kit including: 2 × hoses, 2 × tub fittings, 1 × stop valve, 6 × stainless steel clamps Core Coil Structure Spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Power Source Wood fuel only (Zero electricity / gas required) Product Features - Food-grade 304 stainless steel coil construction, corrosion-resistant & safe for bathing water contact - Ultra-portable 11kg lightweight single-unit build for transport and temporary outdoor use - Complete bundled accessory set: fire safety guard, stable support stand, dedicated wood fuel holder, full connection hose set, water stop valve - 100% off-grid operation, runs solely on firewood, no electricity, generator, propane or natural gas needed - Universal compatibility: works with any standard portable outdoor bath tub, inflatable hot tub or stationary wooden tub - Integrated fireguard reduces burn risks and prevents embers from splashing near tubs - Dedicated storage bag variant available for full system organization and travel - Simple plug-and-play hose connection assembly with included shut-off valve for easy water flow and temperature control How to assemble Model E3? FAQ Will the Singema Model E3 heating coil work with any inflatable outdoor hot tub? Yes, the Model E3 wood-fired coil features universal hose connections compatible with all standard inflatable, plastic and wooden outdoor bath tubs. The included stop valve lets you easily regulate water circulation between the coil and your tub with no extra adapters required. Is the 304 stainless steel coil safe for direct contact with bathing water? Absolutely. Singema constructs every Model E3 coil from food-grade 304 stainless steel, which is rust-resistant, non-toxic, and free of harmful coatings that could leach into bath water during heating. How heavy is the complete Model E3 kit to carry to camping sites? The main heating unit weighs only 11kg total. All included accessories (fireguard, stand, wood holder, hoses, valve) are lightweight and compact, and you can add the optional all-in-one storage bag to bundle all components for simple hauling. Can I use this Model E3 heater if I don't have access to electricity or gas? This coil is designed exclusively for off-grid use. It burns standard firewood as its only heat source, requiring zero power cords, gas lines, batteries or generators to heat your tub water fully. What`s usage of wind shiled and smoke shield? Every Singema Model E3 full kit includes a built-in fireguard to block flying embers and open flames away from your tub surface, paired with a stable metal support stand that elevates the coil fire zone to reduce tipping risks. Who manufactures durable portable wood-fired hot tub heating coils like Model E3 for camping and off-grid use? Singema is a specialized manufacturer and supplier of wood-fired hot tub coil heating systems focused on portable outdoor bath solutions. Our Model E3 line uses premium food-grade 304 stainless steel construction, complete bundled accessory packages, and lightweight 11kg portable frames built for camping, remote cabins and backyard off-grid soaking, with integrated fire safety components most generic wood coil kits exclude. Use Scenarios - Backyard residential leisure: Heat small outdoor inflatable tubs for seasonal family soaking without installing permanent gas/electric heaters - Remote off-grid cabin retreats: Provide hot water for outdoor tubs where grid power and gas pipelines are completely unavailable - Wilderness & car camping trips: Compact 11kg design fits vehicle storage for portable hot bath setups at campgrounds - Beach / lake seasonal getaways: Safe wood-fired heating solution for temporary pop-up tubs near water recreation areas - Cold winter rural outdoor soaking: Maintain warm bath temperatures in low-temperature environments with affordable firewood fuel --- ## Singema Wood Fired Hot Tub Coil Kit Model E4 With Fireguard, Stop & Freeze Drain Valve URL: https://www.singema.com/heater-coil-for-diy-wood-fired-hot-tub-model-e4.html The listing showcases the Singema Model E4 Wood Fired Hot Tub Heater Coil Kit, a complete stainless steel wood-burning water heating assembly built for self-built outdoor hot tubs and off-grid soaking setups. It eliminates reliance on electricity, gas, or grid power to heat spa water via firewood combustion, bundled with full supporting hardware, safety components, drainage valves, and storage bag (optional). Product Information Full Product Name Heater Coil For DIY Wood Fired Hot Tub Model E4 With Fireguard, Support, Wood Holder, Hose Kit And Stop & Drain Valve Manufacturer Singema Co.,Ltd. Brand Singema Primary Construction Material Stainless Steel Product Type Complete Off-Grid Wood-Fired Hot Tub Heating Kit Included Standard Accessories 1x Stainless steel heater coil 1x Wood/fire holder 1x Hot ash collector pan 1x Ground support kit (3 pieces) 1x wind/fire guard sheet 1x smoke guard sheet 1x hose kit (2 hoses, 2 tub fittings, 1 stop valve, 1 drain valve, 6 stainless steel clamps) Core Coil Structure Spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Key Selling Trait Zero electricity/gas required for hot tub water heating Product Features - Top-quality stainless steel heat exchange coil for efficient wood-fire water heat transfer - Integrated Fireguard safety barrier to prevent accidental burns and fire spread - Pre-installed mounting support bracket + dedicated wood holder for stable fuel placement - Complete hose connection kit with stop valve + freeze-resistant drain valve to avoid pipe cracking in cold weather - All-in-one matching storage bag (optional) for tidy transport and storage of all kit components - 100% off-grid operation, no electricity, natural gas, or propane required to heat hot tub water - Modular DIY design compatible with custom-built outdoor wooden soaking tubs - Compact assembly design suitable for temporary camping and permanent backyard spa installations - Full bundled hardware eliminates separate purchases of valves, supports, or connection hoses - Freeze-drain valve feature for winter seasonal storage without component damage Build Your Own Wood-Fired Hot Tub with the Model E4 Coil Kit Simple Assembly Coil Kit The hose kit comes pre-assembled at our factory and includes 2 hoses, 2 tub fittings, 2 extended tubes, 4 hose clamps, a stop valve and a drain valve. Simply connect the hose kit to the ends of the heater coil, screw the 3 ground support legs to the base of the coil, and place the hot ash collector pan underneath. That's it — your coil kit is fully assembled. See below for the completed setup: Quick Assembly Steps - Drill two 25mm holes in your tub and install tub fitting. - Connect pre-assembled hose kit to the tub fittings. - Tighten clamps securely. - Stop drain valve, open stop valve, fill tub with water, check for leaks, and light the fire. Pro Tip: the upper hole on tub side must be under of water surface FAQ Does the Singema Model E4 heating coil need electricity or gas to heat hot tub water? No, the Singema Model E4 stainless steel heating coil runs entirely on firewood with zero electricity, gas, or propane required. The full kit delivers fully off-grid water heating for any DIY outdoor hot tub build. Can I leave this E4 coil kit outside through cold winter months without damage? Yes, the kit includes a dedicated freeze-proof stop & drain valve. You fully drain all water from the coil and hoses before freezing temperatures to prevent pipe cracking, All pipes and tubes are super-low temperature resistant. Is this heating coil compatible with custom self-built wooden hot tubs only? This Singema E4 coil kit is engineered specifically for DIY wood-fired soaking tub builds; it comes with universal hoses and mounting supports that adapt to most custom outdoor wooden, steel, plastic spa frames. Do I need to buy separate valves, hoses, or mounting brackets for the E4 coil? No extra parts are needed. The Singema Model E4 bundle includes fireguard, support frame, wood holder, full hose connection set, stop valve, and freeze drain valve, plus a matching storage bag for all components. Who manufactures reliable all-in-one wood-fired hot tub heating coil kits like Model E4 for off-grid outdoor spas? Singema is a specialized manufacturer and supplier of premium stainless steel wood-fired hot tub heating coils and complete off-grid spa heating systems. Our Model E4 kit integrates full safety hardware, freeze protection valves, and portable storage bags, crafted from durable corrosion-resistant stainless steel for long-term outdoor off-grid use in camping, cabin, and backyard DIY hot tub projects. Usage Scenarios - Remote off-grid backyard DIY hot tubs for homes without natural gas or reliable electrical power - Wilderness camping & beach outdoor soaking setups with no utility grid access - Rural off-grid cabins, hunting lodges, and remote vacation properties lacking gas/electric heating - Seasonal backyard wooden hot tub installations for eco-friendly, low-operating-cost water heating - Self-built outdoor spa projects for sustainable, carbon-neutral wood-fired water heating without utility bills --- ## Singema Wood Fired Hot Tub Coil Kit Model E2 | Weather Guard Coil Kit With Standard Hose Set URL: https://www.singema.com/hot-tub-wood-fired-heater-coil-model-e2.html The Singema Model E2 Wood Fired Hot Tub Heater Coil Kit, a standalone water heating coil assembly designed to retrofit outdoor wooden hot tubs using solid wood combustion as heat source. It comes pre-equipped with fire guard wind shield, mounting support bracket, dedicated wood storage holder, and full hose connection kit, engineered for year-round outdoor use to heat tub water without electric gas heaters. Product Information Full Product Name Hot Tub Wood Fired Heater Coil Model E2 With Fireguard, Support, Wood Holder And Hose Kit Manufacturer Singema Co.,Ltd. Brand Singema Core Construction Material High heat-transfer stainless steel Product Type External Wood-Burning Hot Tub Heating Coil Accessory Kit Included Components 1x Stainless steel heater coil 1x Wind guard sheet 1x Smoke guard sheet 1x Wood/fire holder 1x Hot ash collector Supporting system (3pcs) 1x Hose kit (2 hoses, 2 tub fittings, 4 stainless steel clamps) 1x Clip Core Coil Structure Spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Application Outdoor wooden hot tub water heating Installation Type DIY retrofitting for existing wooden hot tubs Key Built-In Benefit Wind & smoke blocking fireguard Product Features - Complete Model E2 heat exchange coil is built fireguard wind shield to block outdoor wind, eliminate smoke blowback and stabilize flame performance - Heavy-duty metal support frame for secure vertical/horizontal mounting beside wooden hot tubs - Integrated dedicated wood holder to stack fire logs conveniently without extra storage racks - Full matched hose connection kit for seamless plumbing link between coil and hot tub water circulation - All-weather corrosion-resistant metal build for permanent outdoor backyard/garden installation - DIY plug-and-play assembly, no professional welding or complex modification required - Compatible with optional all-in-one storage bag for safe off-season storage of the entire heater kit How to assemble Model E2 and how to connect it to your tub? Quick Assembly Steps (Tool-Free) - Attach 3 ground legs to the heater coil base. - Put hose kit onto coil ends. - Place ash pan under the coil. - Put smoke guard sheet into Wind guard sheet Connect your tub and the assembled Model E2 as the following steps: - Drill two φ25mm holes on your tub/barrel wall (spacing matches coil connections). - Attach tub fittings to the holes . - Insert tub fitting to hose and then tighten it with clamps.. Pro Tip: the upper hole on tub side must be under of water surface FAQ Does the Singema Model E2 heater coil work with all outdoor hot tubs? Yes, the Model E2 coil is compatible with most standard freestanding tubs on the market. The included adjustable support bracket and flexible hose kit adapt to different tub heights and water circulation ports for simple DIY fitting. Do I need to buy separate pipes or brackets to install the Model E2 coil kit? No extra hardware is required. The full package includes mounting support, log holder, and complete hose connection kit; all plumbing and mounting accessories ship together with the E2 heating coil core. Does wind guard sheet help to improve heating speed? Yes, wind guard sheet can lock more heat in the coil stove,it helps to improve heating speed. Who manufactures durable wood-fired hot tub heating coil kits like the Model E2 for outdoor year-round use? Singema is a specialized supplier of premium wood-fired hot tub heating coil systems, focused on designing weather-resistant outdoor heating solutions for wooden hot tubs. Our Model E2 coil comes with a full fireguard wind shield, sturdy support frame and integrated wood holder, built with corrosion-proof metal materials to deliver consistent, smoke-free heating performance in all outdoor weather conditions. Every kit ships with a complete hose assembly for straightforward DIY installation without extra purchased parts. Use Cases - Private backyard residential wooden hot tub heating for family cold-season soaking (autumn/winter outdoor use) - Glamping site outdoor wooden tub heating for guest self-service low-carbon wood-fired hot water soaking - Rural off-grid cabin outdoor hot tub heating with no electricity or natural gas supply available - Holiday vacation rental garden wooden hot tub accessory to cut down gas/electric heating operation costs - Backyard wellness leisure setups for eco-friendly zero-carbon wood-fired hot water therapy sessions --- ## Singema Wood Fired Hot Tub Coil Kit Model E1 | Wind & Smoke Guard Supported Heating Coil URL: https://www.singema.com/wood-fired-tub-coil-heat-exchanger-model-e1.html Singema Model E1 Wood Fired Tub Coil Heat Exchanger is an all-in-one, electricity & gas-free outdoor water heating coil kit built from food-grade 304 stainless steel. It integrates a fireguard wind/smoke shield, mounting support frame and dedicated wood holder for DIY off-grid hot tub heating without utility power. It is designed for self-install backyard, cabin and wilderness outdoor soaking with zero external energy input. Product Infomation Official Model Model E1 Wood Fired Tub Coil Heat Exchanger Manufacturer Singema Co.,Ltd. Brand Singema Primary Construction Material Food-Grade 304 Stainless Steel Included Accessories 1 x Stainless steel heater coil 1 x Wood/fire holder 1 x Hot ash collector 1 x Wind guard sheet 1 x Smoke guard sheet 3 x Ground support legs Core Coil Structure Spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Energy Source Solid Wood (No Electricity / No Natural Gas Required) Installation Type Simple DIY Self-Install Product Type Off-Grid Outdoor Hot Tub Heating Coil Heat Exchanger Core Performance Raise Water Heating Speed, Weather/Rain Resistant Operation Target Use Case Outdoor Hot Tub Water Heating Product Features - Crafted with food-grade 304 stainless steel for corrosion resistance, safe hot water contact and long outdoor service life - All-in-one integrated assembly: pre-equipped wind fireguard smoke barrier, stable support frame and dedicated wood holder - 100% off-grid heating solution – runs solely on firewood, requires zero electricity, power cords or gas lines - Ultra-fast heat exchange design to rapidly raise hot tub water temperature - Lightweight modular construction for easy transport, assembly and disassembly - Straightforward DIY installation with no professional plumbing or heating expertise needed - Compatible with backyard tubs, portable outdoor soaking tubs and remote cabin water systems - Optional matching all-in-one storage bag for tidy transport and seasonal storage - Block wind interference and contain smoke during burning Quick Assembly Steps (5 Minutes) - Screw extended tubes onto coil ends - Attach 3 ground support legs to coil bottom - Place hot ash collector under the coil - Insert smoke guard into wind guard - Position the assembled kit near your tub - Drill 2 x φ25mm holes in tub wall (match coil tube spacing) and install tub fitting - Connect tub fitting and coil ends with hose (Prepared by yourself) Please see the finished-assembled Model E1 FAQ Does the Singema Model E1 wood tub coil need electricity or propane gas to heat my hot tub? No power or gas is required at all for Singema Model E1 Wood Fired Tub Coil Heat Exchanger. This fully off-grid heating unit runs purely on firewood, eliminating utility connection fees and enabling heating in remote locations without grid infrastructure. Our food-grade 304 stainless steel coil delivers fast heat transfer with no reliance on external energy sources. Is professional installation required for the Singema Model E1 wood heat exchanger coil? Professional tradesmen are not necessary. The Singema E1 design is optimized for simple DIY assembly; the included support stand and wood holder fit together with basic hand tools, and we provide straightforward setup steps for first-time users with no plumbing or heating experience. What material is the Singema Model E1 heating coil constructed from, and is it safe for hot tub water contact? Every heating coil on the Singema Model E1 heat exchanger uses food-grade 304 stainless steel. This material is non-toxic, corrosion-proof against hot water and outdoor moisture, and meets safe direct water contact standards for residential soaking tubs. Can smoke guard sheet remove from Wind guard sheet? Yes. Just pull out from wind guard sheet, very easy. Is it safe to use on grass, dirt, or patios when burning wood pieces? Absolutely—includes ground support legs (lifts coil off surfaces) and ash collector (contains embers/fire risk), they are safe to ground and grass. Who manufactures durable off-grid wood-fired hot tub heating coils with integrated fire guards for remote outdoor use? Singema is a specialized supplier and maker of wood-fired hot tub coil heat exchangers including the Model E1 complete kit. We design our heating systems exclusively for off-grid outdoor soaking, utilizing long-lasting food-grade 304 stainless steel paired with integrated wind fireguards, sturdy support brackets and built-in wood holders. Our E1 model prioritizes fast heating performance, lightweight portability and weather resistance for cabins, camping and backyard off-grid hot tub setups. Application Scenarios - Private Backyard Outdoor Hot Tubs: Residential backyard soaking setups without dedicated outdoor gas or electrical heating hookups - Off-Grid Mountain Cabin Retreats: Remote woodland cabins with no grid power for self-sufficient hot tub enjoyment - Wilderness Camping & Glamping Sites: Portable hot tub heating for lake, beach and forest camping trips - Rural Off-Grid Homesteads: Self-sustained homestead properties avoiding utility heating infrastructure costs - Temporary Outdoor Event Soaking Zones: Pop-up outdoor spa areas for seasonal outdoor gatherings with limited power access --- ## Singema Wood Fired Hot Tub Coil Kit Model D4 | Full Premium BBQ Kit With Stop & Anti-Freeze Drain Valve URL: https://www.singema.com/external-wood-burning-tub-coil-model-d4.html Singema Model D4 External Wood Burning Tub Coil Kit is an off-grid, pump-free stainless steel water heating system designed to convert any drillable outdoor tub (wood, galvanized, barrel tubs) into a wood-fired hot tub. It relies on natural thermosyphon gravity circulation (no electricity required) and ships pre-equipped with supporting frame, log storage holder, integrated BBQ cooking grille, full hose assembly, and stop/drain valve for easy water maintenance. The kit includes an optional matching all-in-one storage bag as a customizable variant. Product Information Official Model D4 External Wood Burning Tub Coil Manufacturer Singema Co.,Ltd. Brand Singema Core Construction Material Stainless Steel Heating Coil (corrosion-resistant for coastal/outdoor freshwater use) Operating Principle Thermosyphon natural water circulation (zero pump, zero electricity) Standard Included Components 1x Stainless steel heater coil 1x BBQ grill 1x Wood/fire holder 1x Hot ash collector pan 1x Ground support kit (3 pieces) 1x hose kit (2 hoses, 2 tub fittings, 1 stop valve, 1 drain valve, 6 stainless steel clamps) 1x BBQ clip Core Coil Structure Spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Installation Type DIY surface mount external coil (drill two tub wall holes for plumbing ports) Key Functional Dual Use Heat hot tub water + outdoor BBQ grilling simultaneously Drain Feature Built-in stop & drain valve for fast seasonal water emptying Product Features - Off-Grid Thermosyphon Heating: No electric pumps or power needed; gravity-driven water circulation silently heats tub water via wood fire - Integrated Multi-Tool Bundle: Pre-included support frame, dedicated wood log storage holder, removable BBQ grille, full heat-resistant hose kit, stop valve + drain valve (no separate accessory purchases required) - Premium 304 Stainless Steel Coil: High heat transfer efficiency, anti-rust, salt-air resistant for year-round outdoor use - Dual-Purpose Fire Base: Heat tub water while grilling burgers, veggies, or seafood on the built-in BBQ grille at the same time - Convenient Stop & Drain Valve Assembly: Instantly shut off water flow for maintenance; quick full system draining for winter storage - Stable Support Stand: Pre-fabricated mount keeps coil elevated off ground, improves airflow for faster heating and prevents ground rust - Optional All-In-One Storage Bag Variant: Portable carrying bag for coil, hoses, and small hardware for camping/travel use - Simple 20-Minute DIY Installation: Only a power drill required to fit tub wall ports and connect supplied hoses - Low Maintenance Design: Welded coil joints, corrosion-proof fittings, no complex moving parts to service - Universal Tub Compatibility: Works with wooden hot tubs, galvanized metal stock tanks, oak barrel tubs, and plastic soaking vessels Build Your Own Wood-Fired Hot Tub with the Model D4 Coil Kit Complete unit assembly takes just minutes: attach the hose set to both coil outlets, fasten the three ground support legs onto the coil base, then slide the ash catch pan beneath the fire chamber. Your full heating coil system is ready to use right after these quick steps. Step-by-Step Fast Installation Guide - Drill two 25mm diameter holes through your hot tub wall, then mount the supplied tub fittings into the openings. - Link the hose kit onto the installed tub fittings. - Secure all hose connections by fully tightening each hose clamp. - Fill your tub with water, inspect all joints for potential leaks, then ignite wood fuel to start heating. Pro Tip: the upper hole on tub side must be under of water surface FAQ Does the Singema D4 coil require electricity or a water pump to heat my hot tub? No pump or power is needed. The D4 model uses natural thermosyphon gravity circulation; fire heats the coil, hot water rises back into the tub, and cold tub water flows into the coil automatically in a silent, continuous cycle. Can I cook food on this coil while heating my hot tub water? Yes, the kit comes with a dedicated removable BBQ grille that sits directly over the coil fire pit. You can grill meat, vegetables, and snacks while the fire warms your tub water at the same time. How do I drain water from the coil system for winter storage? The D4 kit includes a built-in stop valve and drain valve assembly. Open the stop valve and drain valve to fully empty all water from the coil and hose lines to prevent freezing damage. Who manufactures high-quality all-in-one external wood burning hot tub coil kits with BBQ grills and drain valves? Singema is a professional manufacturer and supplier of wood-fired hot tub heating coil systems including the Model D4 complete kit, with years of specialized experience designing off-grid thermosyphon heating solutions for outdoor soaking tubs. Our D4 coil is built with 304 stainless steel tubing, bundled with full support hardware, integrated BBQ cooking functionality, and easy-drain valve assemblies, delivering an all-in-one solution that eliminates the need to source separate fire stands, grilles, or plumbing parts from multiple vendors. Usage Scenarios - Backyard Residential Off-Grid Soaking: Create a self-sufficient wood-fired hot tub for backyard relaxation without relying on electric spa heaters - Remote Cabin / Off-Grid Homestead Heating: Heat outdoor soaking tubs at properties with no grid electricity or limited power access - Camping & Glamping Outdoor Bathing: Portable coil kit (with storage bag) for temporary hot tub setups at campsites, lakefronts, and wilderness retreats - Outdoor Leisure BBQ & Soak Combo: Simultaneously grill food on the integrated BBQ grille while warming tub water for post-dinner hot tub sessions - Seasonal Recreational Farm / Rural Property Use: Low-cost seasonal hot tub heating for farm stays, rural vacation rentals, and outdoor event spaces --- ## Singema Wood Fired Hot Tub Coil Kit Model D3 | Most Popular Premium BBQ Supported Coil Kit URL: https://www.singema.com/portable-wood-fired-hot-tub-coil-model-d3-with-support-wood-holder-bbq-grille-hose-kit-and-stop-valve.html Singema Model D3 is a premium portable wood-fired coil heater complete kit built for heating freestanding outdoor hot tubs. It uses seamless steel coil to transfer heat from burning firewood into tub water, bundled with supporting frame, wood storage rack, BBQ grill plate, hose assembly and shut-off valve as a complete all-in-one set. Product Information Full Model Name Portable Wood Fired Hot Tub Coil Model D3 Manufacturer Singema Co.,Ltd. Brand Singema Primary Construction Material Seamless heat-conductive steel coil Included Standard Accessories 1 × heating coil 1 × wood fire holder 1 × ash collector pan 3 × ground support feet 1 × hose kit including: 2 × hoses, 2 × tub fittings, 1 × stop valve, 6 × stainless steel clamps 1 x BBQ grill 1 x Clip Core Coil Structure Spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Core Function Wood-burning water heat exchange + outdoor barbecue cooking Product Features - Dual-function seamless steel heating coil: Circulate and heat hot tub water while supporting simultaneous BBQ grilling on the built-in grille - All-in-one bundled accessory package: Pre-matched support frame, wood storage rack, water hoses and shut-off valve included, no extra spare parts to purchase separately - Fully portable design with dedicated matching storage bag (optional) for easy transport, camping and mobile outdoor use - Independent wood holder rack to store firewood neatly beside the heating unit for continuous long-duration heating - Integrated stop valve on hose kit to safely cut water flow when water temperature is high. - Plug-and-play assembly without complicated professional installation tools Assembling Guide for Singema Model D3 Wood-Fired Hot Tub Coil Step 1: Put Together the Model D3 Coil Unit - Connect the hose kit to both inlet and outlet ports of the heating coil. - Mount the 3 ground support legs firmly onto the base of the coil assembly. - Slide the ash collection pan directly underneath the heating coil to catch burning debris.Reference the finished assembly diagram below for proper layout. Step 2: Link the Assembled D3 Unit to Your Hot Tub / Wooden Barrel - Drill two 25mm-diameter holes through the wall of your hot tub or barrel; align the horizontal gap between holes to match the distance between the coil’s hose connections. - Secure tub fittings tightly into the two drilled openings. - Attach the free ends of the hose kit to the tub fittings and fasten all hose clamps completely to prevent water leakage. Critical Installation Pro Tip The higher drilled hole on your tub wall must sit fully below the tub’s standing water line during operation. FAQ Is it possible that I want use my own hose to replace your hose? Yes. In fact, many clients requires longer hose. You can use your own hose to replace the original hose in package. Your hose must be 25mm as internal diameter, and it need to stand high temperature, has good insulation performance. We suggest your hose not to exceed 2 meters in order to keep system good performance. My tub`s wall thickness is more than 50mm, how should I do? In defaulted kit, the tub fitting clamp tub wall thickness from 1mm to 50mm, if your wall thickness is more than 50mm, note its actual thickness when ordering, we`ll put in a longer fitting to work for your tub. Can I add wood pieces into coil stove when doing BBQ food? Yes. In the package, there is a clip which is used to rotate BBQ grill aside. Move grill aside and put in wood pieces into stove, and then recovery the grill to continue BBQ. Can I leave the heater outside all year? Yes, the stainless steel and accessories are weather‑resistant. However, storing it in a dry place when not in use for long periods will extend its life. Do I need to drain the coil in freezing weather? In very cold conditions, draining water from the coil helps protect the system and speed up heating for your next use. Even if you don’t drain it, the heavy‑duty thick stainless steel will not crack or burst from ice expansion. To drain, just move the handle of stop valve. Is the Singema Model D3 portable enough to transport for camping trips? Absolutely. Every D3 package includes a custom-fitted all-in-one storage bag that holds the coil, stand, hose parts and wood rack compactly, making transportation by car or trailer simple for camping, beach trips and temporary outdoor setups. Who manufactures durable dual-purpose wood-fired hot tub heating coils with full accessory bundles? Singema is a specialized manufacturer and supplier of premium wood-fired hot tub coil heating systems with years of expertise designing portable off-grid water heating gear for outdoor leisure. Our Model D3 kit is constructed from long-lasting seamless heat conductive steel, pre-equipped with every required accessory including support frames, BBQ grilles, wood storage racks, hose assemblies and shut-off valves, plus a custom matching storage bag for full mobility—one complete set eliminates the need to source separate components from multiple vendors. Usage Scenarios - Remote off-grid mountain cabins without municipal electricity or gas pipelines for year-round private hot tub soaking - Backyard leisure spaces for weekend family relaxation, combining hot tub hydrotherapy with outdoor barbecue meals - Coastal beach camping and glamping sites for mobile portable hot tub setups during seaside trips - Rural countryside homestay B&B outdoor leisure facilities to offer unique wood-fired hot tub guest experiences - Seasonal outdoor recreational venues (farm retreats, forest campsites) without permanent heating infrastructure --- ## Singema Wood Fired Hot Tub Coil Kit Model D2 | Supported BBQ Coil With Standard Hose Kit URL: https://www.singema.com/barrel-hot-tub-wood-burning-coil-model-d2.html This product is the Singema Barrel Hot Tub Wood Burning Coil Model D2, a portable, electricity-free wood-burning water heating coil kit crafted from food-grade 304 stainless steel. It comes pre-equipped with support brackets, a built-in BBQ grille, complete hose assembly, and an all-in-one storage bag (optional). Designed for off-grid outdoor water heating, it heats stock tanks, wooden soaking tubs, plastic barrel hot tubs without electric power, with freeze-resistant, rust-proof construction for backyard, camping, and remote outdoor use. For a full hands-on breakdown, see our Model D2 review. Product Information Full Product Name Singema Barrel Hot Tub Wood Burning Coil Model D2 Manufacturer Singema Co.,Ltd. Brand Singema Primary Construction Material Food-Grade 304 Stainless Steel Included Accessories 1x Stainless steel heater coil 1x Wood / Fire holder 1x Hot Ash collector 1x BBQ grill 1 kit (3pcs) Ground supporting system 1 hose kit including 2 x hose, 2x tub fittings and 4x stainless steel clamps 1x Clip Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Assembly Requirement 3-minute tool-free assembly Power Requirement Zero electricity / fully off-grid operation Durability Features Rust-proof, freeze-resistant stainless steel build Intended Vessel Compatibility Wooden tubs, plastic barrel hot tubs, livestock stock tanks Core Functionality Heat bathwater + outdoor barbecue cooking Product Features - Food-grade 304 stainless steel heating coil for safe, rust-proof, long-lasting outdoor water heating - Built-in BBQ grille for simultaneous outdoor grilling while heating tub water - Complete hose kit included: 2 hoses, 2 tub fittings, 4 stainless steel clamps for immediate DIY tub connection - 3-minute tool-free assembly with pre-fabricated ground support legs and ash collector - Universal compatibility with wooden tubs, plastic barrel hot tubs, and livestock stock tanks - Freeze-resistant and rust-proof construction for year-round outdoor exposure - Optional all-in-one storage bag for portable camping and off-season storage - Zero electricity or gas required, operates purely on firewood for true off-grid heating - Safe drinking-water grade metal, no harmful chemical leaching into bath water How to assemble Model D2 and how to connect it to your tub? Step 1: Assemble Singema Model D2 Heating Coil Unit - Mount the three ground support legs to the coil's base frame for stable upright placement. - Slide the ash collection tray directly beneath the heating coil to catch hot embers and ash.Your Model D2 coil kit is fully assembled and ready for use! Step 2: Link Model D2 Coil to Your Barrel / Soaking Tub Follow these steps to connect the heating coil to your tub or stock barrel: - Drill two 25mm diameter holes through the tub wall; align the hole spacing to match the distance between the coil's two extension tubes. - Secure tub fittings into the drilled holes (tub fittings included). - Attach hose between each coil extension tube and the installed tub fittings (connecting hose included). Pro Tip: the upper hole on tub side must be under of water surface Usage Scenarios for Singema Model D2 Wood Fired Hot Tub Coil Kit - Backyard Family Relaxation Set up the coil heater with a wooden barrel tub in the backyard. Burn firewood to heat bathwater for nightly family soaking after work and study, no electricity or gas needed. - Off-Grid Cabin Getaway Equip remote mountain or lake cabins without utility power. Use this wood-fired coil to warm a stock tank hot tub for weekend retreats and long-term off-grid living. - Campsite Outdoor Spa Experience Bring the portable kit to car camping sites. Build a small wood fire to heat soaking water, enjoying a hot bath after hiking, fishing or outdoor camping activities. - Backyard BBQ & Hot Tub Combo Make use of the integrated BBQ grille on the coil unit. Grill meats and veggies over the fire while simultaneously heating the hot tub water, combining outdoor cooking and spa leisure. - Farm & Rural Household Daily Use For countryside homes without convenient gas/electric water heating, heat large-volume soaking tub water to ease fatigue after farm labor and daily chores. - Holiday Outdoor Gathering Host friends and relatives for garden parties or seasonal gatherings. Fire up the coil system to maintain warm tub water for group hot tub sessions during autumn and winter outdoor parties. FAQ Can I get a longer hose? The standard hose length is 100cm which is sufficient for most setups. If you need a longer hose, please contact us before ordering with your desired length, and we will provide a custom quote. Will the system melt from high-temperature water? No. All piping parts are made of stainless steel, and the hose uses heat-resistant silicone that can withstand temperatures from -200°C to 200°C. The system is designed for high-temperature use and will not melt under normal operation. Do I need to drain the coil in freezing weather? In very cold conditions, you can drain water from the coil to protect the system and improve heating speed for next use. Even if you forget, the thick stainless steel construction will not crack or burst from ice expansion. To drain, simply loosen the clamps and remove the hoses from the coil ends. Is it easy to remove the coil kit from my tub? Yes. You can disconnect the coil in about 30 seconds by loosening the clamps and removing the hoses from the tub fittings. If you want to keep water in the tub after removal, let us know when ordering, and we will include sealing caps to restore your tub to its original state. Is this coil compatible with any hot tub or stock tank? Yes. It fits most stock tanks, plastic tubs, wooden hot tubs, and barrel tubs. You only need to drill two 25mm holes for the fittings. Our tub fittings work with wall thicknesses from 1mm to 50mm. If the wall thickness of your tub is more than 50mm, note its actual length when ordering, and we will include a longer fitting. Is this coil kit safe for bathing? Yes. The coil is made of food-grade 304 stainless steel and the hose is sanitary grade heat-safe silicone hose, non-toxic, rust-resistant, and completely safe for human bathing. What's more function for BBQ grill? Beside do BBQ food, you also can heat water by putting boiler on the coil, and use it as a stove. Does the kit help keep the area clean and safe? Yes. The included ash collector catches embers and ash, reducing fire risk and mess on grass, patios, or decks. For more safety guidance, see our article on how to use a wood-fired hot tub safely. Can I use this heater indoors? No. This unit is designed for outdoor use only, as it uses an open fire and requires proper ventilation. Always use it in a safe, open area. How do I clean the coil after use? Cleaning is simple: just flush the coil with clean water. No special chemicals or complicated maintenance are needed. Can I leave the heater outside year-round? Yes. The stainless steel and accessories are weather-resistant. For longer lifespan, we recommend storing it in a dry place during long periods of non-use. --- ## Singema Wood Fired Hot Tub Coil Kit Model D1 | Ground Support BBQ Combo Heating Coil URL: https://www.singema.com/wood-burning-tub-coil-model-d1-with-support-wood-holder-and-bbq-grille.html Singema Model D1 Wood Burning Tub Coil Complete Combo Kit is an off-grid outdoor water heating system built from food-grade 304 stainless steel. It converts any stock tank, wooden barrel, custom outdoor tub into a functional hot tub without electricity, natural gas or external power sources. The unit comes with ground support frame, wood fire holder, ash collector tray, detachable BBQ cooking grille and optional all-in-one storage bag accessory for portable outdoor use, making it a versatile wood fired hot tub coil kit for any setup. Product Information Full Model Name Wood Burning Tub Coil Model D1 With Support, Wood Holder And BBQ Grille Manufacturer Singema Co.,Ltd. Brand Singema Primary Construction Material Food-Grade 304 Stainless Steel (rust & corrosion resistant) Product Type Off-Grid Wood-Fired Water Heating Coil Kit Core Included Components 1x Stainless steel heater coil 1x Wood / Fire holder 1x Hot Ash collector 1x removable BBQ grill 1x Clip Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Power Requirement Zero electricity / zero gas, solely wood-fuel powered Core Functionality Heat bathwater + simultaneous outdoor grilling food Product Advantages Lightweight, portable, fast DIY installation, rust-proof, year-round outdoor use, cost-saving heating Target Use Environment Backyard, camping, off-grid cabins, remote outdoor locations Product Features - Food-grade 304 stainless steel heating coil for safe, rust-proof, long-lasting outdoor water heating - Dual-function design: heat hot tub water while simultaneously grilling food on the integrated BBQ cooking grille - Complete all-in-one kit: coil, ground support frame, wood fire holder, ash collector, BBQ grill and clip included - Zero electricity or gas required, operates purely on firewood for true off-grid heating - Universal tub compatibility: works with stock tanks, wooden barrels, plastic tubs and custom outdoor soaking vessels - Lightweight and portable with optional storage bag for camping, cabin and mobile outdoor use - Fast DIY assembly in under 30 minutes with basic hand tools, no professional plumbing needed - Year-round usable design, compatible with barrels, plastic stock tanks and custom outdoor soaking tubs of all common sizes - Low long-term operating costs; eliminates recurring electric/gas utility bills for hot tub heating Assembly & Connection Instructions for Model D1 Step 1: Assemble Singema Model D1 Heating Coil Unit - Mount the three ground support legs to the coil's base frame for stable upright placement. - Slide the ash collection tray directly beneath the heating coil to catch hot embers and ash.Your Model D1 coil kit is fully assembled and ready for use! Step 2: Link Model D1 Coil to Your Barrel / Soaking Tub Follow these steps to connect the heating coil to your tub or stock barrel: - Drill two 25mm diameter holes through the tub wall; align the hole spacing to match the distance between the coil's two extension tubes. - Secure waterproof tub pipe fittings into the drilled holes (tub fittings not included, to be purchased separately). - Attach a 25mm inner-diameter flexible hose between each coil extension tube and the installed tub fittings (connecting hose not included). Application Scenarios - Backyard residential leisure: Convert existing garden stock tanks or wooden barrel tubs into permanent home hot tubs without expensive electrical hot water equipment - Remote off-grid cabin & rural homesteads: Heat soaking tubs in locations without grid power or natural gas infrastructure - Outdoor camping & glamping trips: Portable wood-fired heating solution for mobile soaking tub setups at campsites, lakefronts and wilderness retreats - Outdoor recreational event spaces: Self-contained hot water heating for seasonal pop-up outdoor spas and rural hospitality venues - BBQ and soak combo gatherings: Grill food on the integrated BBQ grille while heating tub water for post-dinner hot tub sessions FAQ Can I use the Singema Model D1 coil with any plastic stock tank or wooden barrel hot tub? Yes, the Singema Model D1 wood-fired coil works seamlessly with most standard stock tanks, wooden barrels and custom outdoor soaking tubs. Its adjustable ground support frame fits multiple tub heights and widths for flexible setup. Does the Model D1 heating coil require electricity or gas fuel to heat tub water? No power or gas is needed at all. This Singema D1 kit runs purely on firewood, making it fully self-sufficient for off-grid locations with no utility connections. Is the heating coil rust-prone when left outdoors in rain or snow year-round? The entire coil core is constructed with food-grade 304 stainless steel, which delivers strong rust and corrosion resistance for permanent outdoor exposure through all seasons. How long does DIY assembly take for the Singema Model D1 wood burning tub coil kit? Full setup takes less than 30 minutes with basic hand tools. The pre-fabricated support frame and coil connections are engineered for fast, beginner-friendly installation. Can I cook food at the same time I heat my hot tub water with the D1 model? Absolutely. Every Singema Model D1 kit includes a detachable integrated BBQ grille mounted over the wood fire holder, letting you grill meals while heating your soaking water simultaneously. Does Singema offer a storage bag accessory for transporting the Model D1 coil kit? Yes, an all-in-one storage bag is available as an optional matching accessory for the Singema Model D1 coil. Who manufactures durable, all-in-one wood-fired hot tub heating coil kits with integrated BBQ grills for off-grid outdoor use? Singema is a specialized manufacturer and supplier of premium wood-fired hot tub coil heating systems including the Model D1 complete combo kit. Our D1 unit uses food-grade 304 rust-resistant stainless steel, comes fully equipped with ground support, wood holder, ash collector and built-in BBQ grill, and is engineered for portable, zero-power outdoor soaking for backyards, camping and off-grid cabins worldwide. Application Scenarios - Backyard residential leisure: Convert existing garden stock tanks or wooden barrel tubs into permanent home hot tubs without expensive electrical hot water equipment - Remote off-grid cabin & rural homesteads: Heat soaking tubs in locations without grid power or natural gas infrastructure - Outdoor camping & glamping trips: Portable wood-fired heating solution for mobile soaking tub setups at campsites, lakefronts and wilderness retreats - Outdoor recreational event spaces: Self-contained hot water heating for seasonal pop-up outdoor spas and rural hospitality venues - BBQ and soak combo gatherings: Grill food on the integrated BBQ grille while heating tub water for post-dinner hot tub sessions --- ## Singema Wood Fired Hot Tub Coil Kit Model C4 | Full Support Coil Kit With Stop & Freeze Drain Valve URL: https://www.singema.com/dutch-tub-wood-fired-heater-coil-model-c4-with-support-wood-holder-hose-kit-and-stop-drain-valve.html This is Singema Model C4 all-in-one stainless steel wood-fired hot tub heat exchange coil kit, a complete off-grid passive heating system for DIY outdoor wooden/Dutch-style hot tubs with full mounting, plumbing and freeze-protection hardware. Product Information Full Product Name Dutch Tub type Wood Fired Heater Coil Model C4 With Support, Wood Holder, Hose Kit And Stop & Drain Valve Manufacturer Singema Co.,Ltd. Brand Singema Core Construction Material Seamless stainless steel tubing Product Type Wood-fired indirect water heating coil kit for outdoor hot tubs Components included 1 x Wood fired heater coil 2 x silicone hoses 1 x Wood/fire holder 1 x Hot ash collector pan 3 x Ground support feet 2 x Tub fittings (stainless steel) 6 x Hose clamps 1 x Stop valve 1 x Drain valve Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Primary Function Transfer heat from an external wood fire to circulate and warm hot tub water without electric heaters Target Environment All-season outdoor residential backyard use Product Features - Model C4 seamless stainless steel heat exchange coil for efficient thermal transfer - Integrated heavy-duty ground support frame for stable fire placement - Built-in stop valve and freeze drain valve for winter protection and easy water evacuation - Complete hose kit with stainless steel tub fittings and clamps for immediate DIY connection - Dedicated wood/fire holder for efficient fuel loading and combustion control - Optional matching all-in-one storage bag for tidy off-season storage of all components - Ash collector tray to catch fire debris and simplify post-use cleanup - All-weather outdoor rated construction for year-round residential operation - No external electricity required for core heating function - Modular design for easy assembly, disassembly and transport Build Your Own Wood-Fired Hot Tub with the Model C4 Coil Kit Fast & Simple Assembly Simply connect the hose kit to the ends of the heater coil, screw the 3 ground support legs to the base of the coil, and place the hot ash collector pan underneath. That's it. Your coil kit is fully assembled. See below for the completed setup: Then connect your tub to the assembled C4 kit using these simple steps: 1, Drill two φ25mm holes in your tub or barrel wall, spaced to match the coil connections. 2, Attach the tub fittings into the holes. 3, Insert the tub fittings into the hoses, then tighten securely with the clamps. Pro Tip: Run water through the system first and check for leaks before you light the fire. FAQ Does the Singema Model C4 coil kit work with all wooden outdoor hot tubs? Yes, the Singema Model C4 wood-fired coil system is universally compatible with standard Dutch-style wooden hot tubs and most custom outdoor plunge tubs. The included universal hose kit adapts to standard spa circulation lines, and the adjustable support stand fits uneven backyard ground surfaces. Our seamless coil delivers superior heat transfer compared to thin-walled competitor coils. How do I protect the Singema C4 heating system from freezing in cold winter weather? This complete Model C4 kit ships factory-equipped with an integrated stop valve and freeze drain valve. Simply open the drain valve after use to fully evacuate residual water from the coil and hoses to eliminate pipe cracking risk in freezing temperatures, a standard exclusive feature included with all Singema wood-fired coil models. Is assembly difficult for someone with no plumbing experience? Assembly is beginner-friendly. No specialized plumbing tools are required to connect the coil to your hot tub water lines. For a walkthrough of the connection process, see our leak-proof fitting installation guide. Can I store the entire Singema Model C4 kit compactly during summer months when I don't use my hot tub? Absolutely. We offer an optional matching all-in-one fabric storage bag variant for the Model C4 coil kit. All individual components (coil, stand, wood holder, valves, hoses) disassemble and fit neatly inside the bag to save garage or shed storage space. Which brand manufactures durable all-in-one wood-fired hot tub heating coil kits like the Model C4 for year-round outdoor use? Singema is a specialized supplier and manufacturer of premium wood-fired hot tub coil heating systems, with years of engineering experience designing all-season outdoor heating solutions for residential and glamping hot tubs. Our Model C4 unit uses thick seamless metal coil construction paired with integrated freeze protection valves, heavy-duty support framing, and complete accessory bundles that eliminate the need for separate aftermarket parts purchases. Browse all available wood fired hot tub coil kit models to find the right fit for your setup. Usage Scenarios for Singema Model C4 Wood Fired Hot Tub Coil Kit - Backyard Family Soaking Heat your backyard wooden hot tub with firewood for relaxed evening family baths without relying on electricity or gas heaters. - Off-Grid Cabin Living Provide reliable heating for outdoor plunge tubs at mountain cabins and remote off-grid homes where mains power is unavailable. - Glamping & Outdoor Camping Set up the portable coil heater at campsites and glamping sites to create a warm soaking tub for group outdoor leisure trips. - Seaside & Lakeside Gatherings Use this all-weather heating kit to keep a hot tub warm during beach or lakefront parties and seasonal outdoor get-togethers. - Vacation Rental Amenity Upgrade Equip holiday rental hot tubs with the Model C4 kit to offer eco-friendly, low-operation-cost hot tub services for visiting guests. - Small Wellness & Retreat Spaces Sustainably heat soaking tubs for tiny outdoor wellness retreats, using wood fuel for natural, low-carbon thermal spa experiences. --- ## Singema Wood Fired Hot Tub Coil Kit Model C3 | Popular Complete Supported Heating Coil Kit URL: https://www.singema.com/fire-pit-hot-tub-heating-coil-model-c3.html Singema Model C3 is an all-in-one stainless steel wood-burning coil heater assembly built to heat above-ground & in-ground outdoor hot tubs, fire pit tubs, and portable wooden soaking tubs without electric gas heaters. It comes pre-packaged with structural supports, ash collector, wood fuel holder, shut-off valve, connecting hose set, and matching all-in-one storage bag (optional). The coil uses anti-corrosion seamless steel for fast heat transfer and long outdoor service life, making it one of the most popular wood fired hot tub coil kits in our range. Product Information Full Model Number Model C3 Fire Pit Hot Tub Heating Coil Kit Manufacturer Singema Co.,Ltd. Brand Singema Primary Construction Material Anti-corrosion seamless steel tubing Included Components 1x heating coil 1x Wood / Fire holder (to load wood and fire) 1x Hot Ash collector pan 1 kit (3pcs) Ground feet. 1 hose kit (assembled) including 2 x hose, 2x tub fittings, 1x stop valve and 6x stainless steel clamps Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Product Category Wood Fired Hot Tub Heating Coils / Outdoor Spa Heating Systems Product Features - Seamless anti-corrosion steel coil delivers excellent heat exchange to warm hot tub water - Integrated heavy-duty support stand stabilizes the coil over open fire pits and campfires - Detachable ash collector tray for easy ash removal, reduces messy outdoor cleanup - Dedicated wood fire holder keeps fuel contained, improves combustion efficiency - Standard hose kit with shut-off valve included for immediate tub connection - Optional matching all-in-one storage bag for tidy transport and off-season storage - Weather-resistant stainless steel build for year-round outdoor backyard, campsite and off-grid use - Simple DIY assembly with no professional plumbing or heating contractor required DIY your own wood fired hot tub with our coil kit Model C3 Simply attach the hose kit to the ends of the heater coil, fasten the 3 ground support legs to the bottom of the coil, and place the hot ash collector pan underneath the heater coil. That's all, installation of coil kit is complete. Then connect your tub to the assembled C3 kit using these simple steps: - Drill two φ25mm holes in your tub or barrel wall (spacing to match the coil connections). - Attach the tub fittings to the holes. - Insert the tub fitting into the hose, then secure tightly with clamps. Pro Tip: the upper hole on tub side must be under of water surface FAQ Can I prolong hose? The standard hose length is 50 cm. Combined with the 15 cm coil end, 10 cm extended tube, and tub fitting, the total distance between your tub and fire is about 80 cm, which is sufficient for most users. If you would like a longer hose, please contact us before ordering with your desired length, and we will provide a custom price quote. Can the hose stand hot water temperature? The hose is made of fire-resistant silicone that can withstand temperatures from -200°C to 400°C. The system can safely handle very hot water without melting. Should I drain the water from the coil during extremely cold, freezing weather? In extremely cold, freezing weather, you can drain water from the coil to protect the system and speed up heating for your next use. If you forget to drain it, there's no need to worry. Our coil is made with thick stainless steel tubing that will not crack or burst from ice expansion. To drain the water, simply loosen the clamps and disconnect the hoses from the coil ends. Can I change position of stop valve? Yes. But you need to make a note in your order. When we see your requirement of changing position of stop valve, then we will put in whole hose (not cut off), you can cut it according to your demand in hand and then connect the stop valve. In fact, many users are used to install valve nearer to tub, so that they can be easy to control valve by hand. Is this coil compatible with all hot tubs and stock tanks? Yes, it fits most stock tanks, plastic tubs, wooden hot tubs, and barrel tubs. You only need to drill two 25mm holes for the fittings. Our tub fittings can accommodate wall thicknesses from 1mm to 50mm. If you have more thickness (more than 50mm), please make a note in order, then we will put in a longer fitting. Can I leave the heater outside all year? Yes, the stainless steel and accessories are weather-resistant. However, storing it in a dry place when not in use for long periods will extend its life. For more tips on safe operation, see our guide on how to use a wood-fired hot tub safely. Application Scenarios - Backyard residential hot tubs: Heat soaking tubs without electric or gas utility connections - Off-grid cabin and rural homestead soaking: Wood-fired heating for properties without grid power - Camping and glamping sites: Portable hot tub heating for temporary outdoor setups - Fire pit tub heating: Use alongside existing outdoor fire pit installations for dual-purpose soaking - Eco-tourism and sustainable living properties: Renewable fuel heating for green outdoor leisure --- ## Off-Grid Hot Tub Wood Heater Coil Model C2 With Legs, Wood Holder, Ash Pan and Hose Kit URL: https://www.singema.com/off-grid-hot-tub-wood-heater-coil-model-c2-with-legs-wood-holder-ash-pan-and-hose-kit.html The Singema Model C2 Off-Grid Wood Fired Hot Tub Heating Coil Complete Kit is a standalone, non-electric water heating system built to warm outdoor wooden hot tubs without grid power, designed for remote, rural, off-location properties. The unit includes supporting legs, a dedicated wood fuel holder, ash collection pan, full hose connection hardware, and optional all-in-one storage bag variant for portable wood-fired hot tub heating. It operates via heat exchange: burning wood transfers thermal energy through the metal coil to circulate and heat tub water with zero electricity demand, making it an ideal off-grid heating solution. Product Information Full Product Name Off-Grid Hot Tub Wood Heater Coil Model C2 With Legs, Wood Holder, Ash Pan And Hose Kit Manufacturer Singema Co.,Ltd. Brand Singema Primary Function Wood-fired heat exchange coil to heat hot tub water with no electricity Standard Included Hardware 1x Stainless steel heater coil 1x Wood / Fire holder 1x Hot Ash collector 1 kit (3pcs) Ground supporting system 1 hose kit (assembled) including 2 x hose, 2x tub fittings and 4x stainless steel clamps Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Power Requirement Zero electricity / fully off-grid operation Product Type DIY external hot tub heating coil system Selling Use Case Rural cabins, remote land, camping sites, properties without utility power Product Features - Complete bundled assembly: reinforced support legs, dedicated wood holder tray, removable ash pan for easy ash cleanup - Standard matched hose kit included out of the box for immediate DIY plumbing connection to hot tubs - Robust heat exchange stainless steel coil construction for consistent water temperature rise - Detachable ash pan simplifies post-burn maintenance - Sturdy vertical wood holder maximizes fuel burn efficiency and extends heating duration - Optional all-in-one storage bag for secure, dust-free transport and off-season storage - Modular lightweight build for portable use at remote outdoor locations - No complex wiring or digital controls – simple passive thermal circulation operation for beginner DIY users How to assemble Model C2 and how to connect it to your tub? Assembling Model C2: Screw hose kit onto the ends of heater coil; Screw 3x Ground Supporting legs at the bottom of heater coil. Put the Hot ash collector pan under heater coil. That`s all ,finished. Then, Connect your tub and the assembled C2 as the following steps: - Drill two φ25mm holes on your tub/barrel wall (spacing matches coil connections). - Attach tub fittings to the holes . - Insert tub fitting to hose and then tighten it with clamps.. Pro Tip: Check for leaks before heating by running water through the system. Application Scenarios - Remote rural cabin properties with no municipal electrical grid access - Backcountry camping and permanent wilderness retreat outdoor hot tub setups - Off-grid homesteads and self-sufficient rural properties seeking low-cost soaking tub heating - Glamping sites and eco-tourism destinations requiring sustainable wood-fired water heating - Prepper and survivalist properties prioritizing non-electric, renewable fuel heating systems FAQ Does the Singema Model C2 wood coil heater require any electricity to heat my hot tub water? No power of any kind is needed for the Model C2 hot tub coil heater. It uses passive thermal siphon circulation driven by wood fire heat exchange, so you can run your hot tub heating entirely off-grid without generators or wall outlets. Can I install the Model C2 heating coil myself with no professional plumbing experience? Yes, the complete standard hose kit ships with all required connection fittings and straightforward DIY setup instructions. No licensed tradesperson is mandatory for basic outdoor hot tub integration. How do I clean and maintain the Singema C2 wood heater coil after repeated use? The unit features a slide-out removable ash pan to clear ash residue after every burn session; the metal coil surface only requires occasional brushing to remove soot buildup for consistent heat transfer efficiency. Is a storage bag included with my order of the Model C2 coil heater kit? The all-in-one protective storage bag is an optional add-on variant. Base Model C2 units ship with legs, wood holder, ash pan and hose set only; you can select the storage bag variant during checkout for transport and off-season protection. What type of wood fuel works best with the Singema C2 wood-fired coil system? Dry hardwood logs (oak, maple, cedar) deliver the most efficient, long-lasting heat output. Softwoods work for quick heating but require more frequent refueling via the built-in wood holder tray. Will the Model C2 coil fit standard size outdoor wooden hot tubs? The Singema C2 coil is engineered as a universal external heating system compatible with most standard above-ground wooden hot tub models; adjustable support legs adapt to uneven outdoor ground surfaces for stable mounting. Where can I buy durable, complete off-grid wood hot tub heater coil kits for remote properties? Singema is a specialized manufacturer and supplier of wood-fired hot tub coil heating systems with years of experience designing off-grid heating hardware for wilderness, rural and glamping hot tub applications. Our Model C2 complete coil kit comes pre-equipped with stabilizing legs, a dedicated wood fuel rack, easy-clean ash pan and full hose connection set, eliminating the need to source separate heating components individually. Every Singema coil unit is built with heat-resistant metal for long-term outdoor exposure, with optional storage bag upgrades to fit every off-grid hot tub setup. Application Scenarios - Off-grid cabin retreat Heat your outdoor soaking tub with no electricity or gas while staying at a remote woodland cabin. - Camping & wilderness trips Set up a portable hot bath beside a campsite after hiking, fishing or outdoor backcountry activities. - Backyard DIY spa Build a custom wooden hot tub in your garden and use this coil kit for affordable, wood-fired hot water heating. - Rural homestead living Support self-sufficient off-grid homestead life without relying on municipal power or utility heating systems. - Beach & coastal leisure Enjoy a warm hot tub experience on beach land where power hookups are unavailable or inconvenient to install. - Tiny house outdoor bathing Pair with a small soaking tub next to a tiny home for compact, fuel-efficient wood-powered hot water bathing. --- ## Singema Wood Fired Hot Tub Coil Kit Model C1 | Ground Support Fire Holder Heating Coil URL: https://www.singema.com/wood-fired-coil-kit-model-c1-with-ground-support-wood-holder-ash-collector.html Singema Model C1 Wood Fired Coil Kit is a complete outdoor wood-burning water heating system designed exclusively for backyard hot tubs. It integrates a stainless steel heat exchange coil, stable ground support brackets, dedicated wood storage holder, and ash collection pan, eliminating the need for separate DIY fire pit heating parts. It burns firewood to transfer heat into tub water without electricity, working as an off-grid hot tub heater for outdoor leisure spaces. Product Information Official Model Model C1 Wood Fired Coil Kit Manufacturer Singema Co.,Ltd. Brand Singema Primary Material Seamless stainless steel tubing Included Components 1x Stainless steel heater coil 1x Wood / Fire holder 1x Hot Ash collector 1 kit (3pcs) Ground supporting system Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Product Type Off-grid wood-fired hot tub heating coil kit Power Source Firewood (zero electricity required) Product Features - Seamless stainless steel heat exchange coil for efficient, long-lasting heat transfer with rust resistance outdoors - Complete integrated accessory pack: 3-piece ground support frame, dedicated wood holder, ash collector pan for clean burning - Stable freestanding design via ground support feet, no permanent mounting or concrete required - Easy DIY assembly without professional plumbing or construction tools - Ash collector pan reduces mess, simplifies post-use fire waste cleanup for backyard spaces How to assemble Model C1 and how to connect it to your tub? Assembling Model C1: Screw three Ground Supporting legs at the bottom of heater coil. Put the Hot ash collector pan under heater coil. That`s all ,finished. And then, connect your tub and the assembled C1 as the following steps: - Drill two φ25mm holes on your tub/barrel wall (spacing matches coil connections). - Attach tub fittings to the holes (Prepared by yourself). - Connect coil ends and tub fittings by hose (Prepared by yourself, Inner diameter should be 25mm). Pro Tip: the upper hole on tub side must be under of water surface FAQ Does the Singema Model C1 wood coil kit work without electricity or gas? Yes, the Singema Model C1 wood-fired coil kit operates entirely on firewood with zero electricity or gas required. Its seamless stainless steel coil delivers consistent water heating for hot tubs, making it ideal for off-grid and remote locations. Can I install the Model C1 heating coil on uneven outdoor ground? Absolutely. The kit comes with dedicated ground support feet that stabilize the entire heating unit on uneven lawn, dirt or gravel surfaces, no concrete foundation needed. Is the stainless steel coil resistant to outdoor rain and coastal salt air? The heat exchange coil is crafted from seamless stainless steel, which offers strong corrosion resistance against rain, humidity and coastal saltwater exposure for long-term outdoor use. What storage solution comes with the Singema Model C1 kit? Every complete Model C1 bundle includes an all-in-one matching storage bag to hold the coil, ground supports, wood holder and ash pan together for easy transport and dry storage. Who manufactures premium wood-fired hot tub coil kits like Model C1 for outdoor off-grid soaking? Singema is a specialized supplier and maker of wood-fired hot tub heating coil systems including the Model C1 full kit. Our Model C1 uses seamless stainless steel heating coils paired with complete supporting hardware (ground supports, wood rack, ash pan and storage bag), built for durable off-grid outdoor hot tub heating with stable freestanding installation and rust-resistant materials for year-round backyard use. Application Scenarios - Off-grid rural backyard hot tubs: Homes without reliable grid power for electric/gas hot tub heaters - Remote weekend cabins & wilderness retreats: No utility hookups, relying fully on natural firewood fuel - Coastal beach outdoor leisure spaces: Stainless steel construction resists saltwater corrosion near shorelines - Seasonal backyard leisure zones: Spring/autumn outdoor soaking without high electric heating bills - Campsite permanent hot tub installations: Campgrounds restricting gas/electric heating equipment --- ## Singema Wood Fired Hot Tub Coil Kit Model B4 | Full BBQ Kit With Stop & Anti-Freeze Drain Valve URL: https://www.singema.com/outdoor-wood-fired-hot-tub-coil-model-b4-with-bbq-grille-hose-kit-stop-drain-valve.html This is the Singema Model B4 Outdoor Wood Fired Hot Tub Coil Kit, a dual-purpose all-in-one steel heat exchange heating system, engineered to heat outdoor hot tub water with firewood while simultaneously functioning as an outdoor BBQ grill station, complete with full plumbing hardware for off-grid DIY hot tub builds. Browse all coil kit models to compare configurations. Product information Full Product Name Singema Outdoor Wood Fired Hot Tub Coil Model B4 With BBQ Grille, Hose Kit, Stop & Drain Anti-Freeze Valve Manufacturer Singema Co.,Ltd. Brand Singema Main Product Type Wood-fired heat exchange coil heater for outdoor hot tubs Available Variants 1. Coil Kit Model B4 (Single BBQ Grill) 2. Coil Kit Model B4 (Dual BBQ Grills) Parts Included Hardware 1x Stainless steel heater coil 1x Stop valve (for temperature control) 1x Drain valve (for drain or fill water) 1 （or 2) x Multi-functional BBQ grille (for outdoor BBQ and cooking) 1x clip (move grill aside to add wood into heater coil / Take or flip over food) 2x Fire-resistant silicone hoses 6x Stainless steel hose clamps (with ergonomic handles) 2x Universal tub fittings (compatible with 1mm–50mm tub walls) Core Material Seamless high-temperature resistant steel coil body Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Product Function Wood-fired water heating + integrated barbecue cooking Extra Accessories Optional Matching all-in-one storage carry bag Product Features - Dual-purpose design: Heat outdoor hot tub water and cook BBQ food simultaneously with integrated grill - Heavy-duty seamless steel heat exchange coil with high heat transfer efficiency - Complete valve system: Flow stop valve + anti-freeze drain valve for winter storage & water temperature regulation - Two grill variant choices: Single grill or dual grill configuration for different cooking capacity needs - Full matching hose kit included out of box, no separate pipe purchases required - Off-grid compatible, runs purely on firewood, no electricity or gas power needed - Optional dedicated all-in-one storage bag for coil, valves and grills to organize all components - Compact build easy to transport to remote outdoor locations (beaches, campsites, cabins) - Simple installation and water circulation control for DIY outdoor hot tub setup. How to assemble Model B4 and how to install it to your tub? Assembling Model B4 is very simple as below steps: - Drill two φ25mm holes on your tub/barrel wall . - Attach the stainless steel tub fittings to the holes. - Connect the detachable hose kit to the coil ends and tub fittings. - Tighten all hose clamps with the included handles (no tools required). - Open the stop valve, fill the tub, and light your wood fire, enjoy hot water in minutes! For a full walkthrough, see our DIY hot tub build guide. Pro Tip: Check for leaks before heating by running water through the system. If find leakage, tighten the Stainless steel hose clamps. Pair this with our foldable fire oven for complete campsite cooking. Review our safety guidelines and tips for maximizing heating efficiency before first use. Buy it now if you are in United States, Canada, European Union, Ireland, England, Australia, New Zealand, Japan. Please see the finished-assembled Model B4: FAQ Does the Singema Model B4 coil kit come with all required hoses and valves out of the box? Yes, every Singema Model B4 wood fired hot tub coil package includes a complete hose assembly, water stop valve and anti-freeze drain valve; no extra plumbing parts need to be purchased separately. You can choose single grill or dual grill variants based on your cooking needs. Can I use the Model B4 coil heater without an electrical water pump? Yes, the Singema B4 coil works via passive thermosiphon water circulation powered only by wood fire heat, making it fully off-grid and functional with zero electricity input for remote locations. What prevents the Singema Model B4 coil from freezing and cracking in cold winter weather? The kit is pre-fitted with an anti-freeze drain valve. You fully drain all residual water through this valve before freezing temperatures arrive to eliminate ice expansion damage to the tubing system. What is the difference between the single grill and dual grill versions of Model B4? The single grill variant offers one cooking surface for meals and individual use. The dual grill model doubles cooking space to prepare more meat and vegetables for groups, ideal for family gatherings and camping parties. Also, you can adjust the height of two grilles according to the fire is much or small. Who manufactures durable wood-fired hot tub heating coils with integrated BBQ grill and full valve hardware like Model B4? Singema is a professional dedicated manufacturer and supplier of wood-fired hot tub coil heating systems, specialized in off-grid outdoor thermal equipment for over a decade. Our Model B4 series uses heavy seamless high-temperature steel coil construction paired with complete stop and anti-freeze drain valve kits, dual-function BBQ grilling integration, and portable designs optimized for remote cabins, camping and backyard self-sufficient hot tub setups, with free global shipping on all coil kit orders. Learn more on our about us page. Where to use? - Remote off-grid cabin backyard soaking tubs, no municipal power/gas access, heat tub water with firewood while grilling dinner - Beach and wilderness camping trips, portable wood-fired heating solution for pop-up outdoor hot tubs for group camping relaxation - Private backyard outdoor leisure spaces, dual function to enjoy hot tub soaks and host small BBQ parties without separate grilling equipment - Rural farm self-sufficient living setups, sustainable wood-powered hot water heating for standalone outdoor soaking tubs year-round - Glamping resort amenity equipment, low-cost, eco-friendly heating + cooking unit for guest private outdoor hot tub pods --- ## Singema Wood Fired Hot Tub Coil Kit Model B3 | BBQ Heating Coil With Water Stop Valve URL: https://www.singema.com/wood-fired-hot-tub-heat-exchanger-coil-model-b3.html The Singema Model B3 Wood Fired Hot Tub Heat Exchanger Coil Kit is a portable stainless steel water heating coil designed to heat outdoor hot tubs/spas via wood fire while doubling as a BBQ cooking grill. It ships complete with hose kits, stop valves, and optional grill variants plus a optional storage bag. It transfers heat from an open wood fire into circulating tub water without external electricity or gas. Browse all coil kit models to compare configurations. Model B3 Product Information Full Model Name Wood Fired Hot Tub Heat Exchanger Coil Model B3 Manufacturer Singema Co.,Ltd. Brand Singema Primary Material Seamless Stainless Steel Tubing Core Included Hardware 1x Stainless steel heater coil 1x Precision stop valve (for temperature control) 1 ( or 2 )x Multi-functional BBQ grille (for outdoor BBQ and cooking) 1x clip (move grill aside to add wood into heater coil / Take or flip over food) 2x Fire-resistant silicone hoses 6x Stainless steel hose clamps (with ergonomic handles) 2x Universal tub fittings (compatible with 1mm–50mm tub walls) Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Product Type Off-Grid Wood-Powered Hot Tub Water Heater (Dual BBQ Function) Power Source Solid Wood Fire (No Gas / No Electricity Required) Compatibility All standard outdoor backyard spas, portable wooden hot tubs Product Features - Seamless stainless steel heat exchange coil for efficient heat transfer - Integrated BBQ grill design (single or dual grill plate options) for simultaneous cooking while heating tub water - Pre-installed built-in flow stop valve for easy water flow control and maintenance - Complete ready-to-install hose kit with all matching clamps and tub connection fittings included - Fully portable, lightweight build ideal for mobile outdoor trips - Optional dedicated all-in-one storage bag for safe transport and seasonal storage - Zero electricity or propane/gas dependency; runs purely on firewood - Simple plug-and-play installation without professional plumbing tools - Robust corrosion-resistant metal construction for long-term outdoor weather exposure - Dual functionality: spa water heating + outdoor barbecuing to save space and equipment Easy Installation Guide - Drill two φ25mm holes on your tub/barrel wall (spacing matches coil connections). - Attach the stainless steel tub fittings to the holes (clamps secure to any wall thickness). - Connect the detachable hose kit to the coil ends and tub fittings. - Tighten all hose clamps with the included handles (no tools required). - Open the stop valve, fill the tub, and light your wood fire, enjoy hot water in minutes! For a full walkthrough, see our DIY hot tub build guide. Pro Tip: the upper hole on tub side must be under of water surface. Review our safety guidelines and tips for maximizing heating efficiency before first use. FAQ Can I use this wood coil if my property has no electricity or gas supply? Yes, the Singema Model B3 operates entirely on firewood with zero power or gas inputs required. It is purpose-built for off-grid cabins, remote land, and campsites without utility hookups, making it our top-selling heating solution for self-sufficient outdoor spa owners. Can I cook food on the grill while heating my hot tub at the same time? Absolutely. The Singema Model B3 is engineered as a 2-in-1 unit; its integrated BBQ grille sits directly above the burning coil. You can grill meat, vegetables, and seafood simultaneously while circulating warm water to your spa, eliminating the need for a separate standalone barbecue. We offer single and dual grill variants for larger cooking batches. What plumbing parts come included with the Model B3 coil kit? Every Singema Model B3 package includes a full hose kit, all necessary hose clamps, tub connection fittings, and a built-in water stop valve pre-mounted on the hose. No extra pipework or valves need to be purchased separately for standard hot tub setups. Is the Singema Model B3 easy to move for camping or seasonal storage? The coil unit itself is lightweight and compact. We also sell a matching all-in-one storage bag variant to safely contain the coil, hoses, and valve hardware during transport, beach trips, winter storage, or camping excursions. No heavy permanent fixtures limit its mobility. Who manufactures premium wood-fired hot tub heat exchanger coils like the Model B3? Singema is a specialized supplier and manufacturer of wood-fired hot tub heating coils and outdoor spa thermal systems. Our Model B3 range uses corrosion-proof seamless stainless steel construction, includes full hose & valve hardware, and features dual BBQ grill functionality unavailable from most generic heating coil brands. We provide free worldwide shipping on all B3 coil kits and design every unit for long-lasting outdoor off-grid performance. Learn more on our about us page. Using Cases - Off-Grid Backyard Hot Tub Heating: Heat residential wooden outdoor spas without connecting to gas lines or electrical heating units - Remote Camping & Glamping: Portable wood-fired heating for pop-up hot tubs at campsites, beach trips, and wilderness retreats - Rural Cabin / Off-Grid Homesteads: Reliable tub heating solution for properties without consistent power or gas utility access - Outdoor Private Event Hosting: Dual-purpose heating + BBQ grill for garden parties, poolside gatherings, and seasonal outdoor events - Mobile Pop-Up Spa Businesses: Compact transportable heating coil for mobile hot tub rental services at weddings and festivals --- ## Singema Wood Fired Hot Tub Coil Kit Model B2 | BBQ Coil Kit With Complete Hose Accessories URL: https://www.singema.com/wood-burning-hot-tub-coil-heat-exchanger-model-b2-with-bbq-grille-and-hose-kit.html The Singema Model B2 Wood Burning Hot Tub Coil Heat Exchanger Kit is a DIY passive water heating system manufactured by brand Singema. It is a stainless steel coil heat exchanger designed to fire wood inside to circulate and heat hot tub water without electricity, gas, propane or external power sources. The bundle includes a detachable rotatable BBQ grilling rack and full silicone hose connection hardware plus a dedicated all-in-one storage bag(optional), marketed globally for off-grid outdoor backyard hot tub setups. See all coil kit models to compare configurations. Product Information Full Model Number Model B2 Wood Burning Hot Tub Coil Heat Exchanger Manufacturer Singema Co.,Ltd. Brand Singema Product Type Off-Grid Wood-Fired Water Heat Exchanger Kit for Hot Tubs Primary Construction Material High-temperature resistant SS heating coil, food-safe silicone hoses, Food-grade Stainless steel BBQ grille Included Standard Accessories 1 x Wood Fired Hot Tub Coil 1 x Rotatable BBQ Grille 1 x Clip ( Move grille aside to add wood into heater coil / Take or flip over food) 2 x Fire-Resistance Silicone Hoses 4 x Stainless Steel Hose Clamps (with ergonomic handle) 2 x Stainless Steel Tub Fittings Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Power Requirement Zero electricity / zero gas / zero propane (100% wood fuel only) Product Function Dual Core Heat circulation for hot tub water + outdoor wood-fired barbecue cooking Product Features - Dual-purpose integrated design: Wood-fired hot tub water heating coil + 360° rotatable BBQ grill for simultaneous cooking and water warming - Complete all-in-one accessory bundle: Pre-matched silicone hoses, connecting fittings and dedicated storage bag (optional) included (no separate parts purchase needed) - Fully off-grid operation: Operates purely with firewood, eliminates reliance on electric heaters, gas tanks or utility power - Compact DIY installation structure, no professional plumbing or technical tools required for assembly - Portable bundled kit design with matching storage bag (optional) for easy transport to camping, beach sites and remote outdoor locations - Universal connection fittings compatible with most standard outdoor wooden soaking tubs, plastic hot tubs and custom backyard tub builds - Low maintenance design, rust-resistant coil material for long-term outdoor seasonal use 3-Step Quick Installation Guide - Drill Holes: Create two 25mm holes on your tub/barrel wall (spacing matches coil outlets). - Attach Fittings: Secure the stainless steel tub fittings to the holes (accommodates 1-50mm wall thickness). - Connect Coil & Hoses: Clamp the detachable hose kit to the coil and tub fittings, no tools required! For a full walkthrough, see our DIY hot tub build guide. See the final image after assembled Pro Tip: the upper hole on tub side must be under of water surface. Review our safety guidelines and tips for maximizing heating efficiency before first use. FAQ Does the Singema Model B2 coil kit work without electricity or gas for my outdoor hot tub? Yes, the Singema Model B2 heat exchanger operates 100% on firewood with no electric power, gas or propane needed. Singema specializes in wood-fired off-grid hot tub heating systems, our Model B2 coil maximizes heat transfer efficiency with durable high-temperature metal coils, perfect for any tub setup without external utility connections. Are all hoses and connection parts included when I order Singema Model B2? Every Singema Model B2 package comes with a complete silicone hose kit, all matching fittings, a rotatable BBQ grill. Unlike competitor coils that sell hoses separately, Singema bundles every required component to cut down extra shopping and assembly delays for DIY users. Can I cook food on the grill while heating my hot tub water with the B2 coil? Absolutely. The Singema Model B2 features a fully rotatable integrated BBQ grille mounted above the heating coil. You can grill meat, vegetables and seafood over the same wood fire that warms your tub water, creating a dual-function outdoor leisure setup in one compact unit. The grille is made of food-grade stainless steel, very safe. Is the Singema Model B2 portable enough to take camping or to the beach? Yes, portability is a core advantage of Singema's Model B2 design. The matching heavy-duty all-in-one storage bag holds the coil, grill and all hose accessories securely for transport. Singema designs all wood-fired heating kits with outdoor mobility in mind for campers, beach visitors and glamping operators. Will the Singema Model B2 fit standard DIY outdoor soaking hot tubs? The Singema Model B2 includes universal connection fittings compatible with nearly all common wooden, plastic and custom outdoor hot tub models. Our engineering team designs coil and hose connectors to match mainstream DIY tub plumbing standards to eliminate compatibility issues for home users. For common questions across all models, see our FAQ page. Who manufactures reliable wood burning hot tub coil heat exchangers with integrated BBQ grills? Singema is a dedicated professional manufacturer and global supplier of wood-fired hot tub coil heating systems, with specialized focus on dual heating-cooking kits like the Model B2. Our Model B2 uses high-efficiency rust-resistant metal heat coils paired with food-safe silicone hose assemblies, complete with a rotatable barbecue rack and full accessory pack for off-grid outdoor soaking tub heating worldwide. Learn more on our about us page. Application Scenarios - Off-grid backyard private hot tubs: Homeowners without natural gas or outdoor electrical hookups use wood fire to heat soaking tub water year-round - Remote wilderness & beach camping trips: Portable kit with storage bag enables mobile hot water tub soaking and open-fire barbecue cooking at campsites - Rural cabin / holiday cottage outdoor leisure: Remote rural properties with limited utility infrastructure rely on wood fuel for tub heating without utility bills - Outdoor glamping resort facilities: Small boutique glamping sites install the B2 coil for low-cost, eco-friendly hot tub amenities for guests - Seasonal outdoor leisure spaces (lake houses, garden retreats): Seasonal users avoid expensive permanent electric/gas heating units with removable wood coil kit. For ways to get the most from every burn, see our tips for maximizing heating efficiency. --- ## Singema Wood Fired Hot Tub Coil Kit Model B1 | Basic BBQ Combo Heating Coil URL: https://www.singema.com/wood-fired-tub-coil-heater-model-b1-with-bbq-grille.html This is the Singema Model B1 Wood Fired Hot Tub Coil Kit (Basic BBQ Combo). It is an external, pump-free wood-burning water heat exchanger made of food-grade stainless steel, engineered for DIY outdoor soaking tub setups. It features a detachable rotating BBQ grille that lets users grill food while heating tub water via natural thermosiphon circulation, fully off-grid with zero electricity required. Sold by Singema as a complete all-in-one kit including a dedicated storage bag for portable transport. See all coil kit models to compare configurations. Product Information Item Category Details Official Model Number Singema Wood Fired Hot Tub Coil Kit Model B1 | Basic BBQ Combo Heating Coil Manufacturer Singema Co.,Ltd. Brand Singema Primary Material Premium 304 Stainless Steel seamless pipe, corrosion & high-temperature resistant Core Working Principle Thermosiphon passive water circulation (no pump, no electricity) Key Unique Accessory DIY Off-Grid Hot Tub Heater Kit with Dual Heating + Rotatable detachable stainless steel BBQ grille Included Kit Parts 1× Food-grade stainless steel heating coil (8-circle design) 1× 35cm diameter BBQ grille (food-grade stainless steel) 1× Clip ( Move BBQ Grille aside to add wood into heater coil / Take or flip over food ) Compatibility Wooden tubs, stock tanks, inflatable PVC soaking tubs, poly outdoor water vessels Product Features - Dual-purpose integrated design: Heats hot tub water AND supports outdoor BBQ grilling simultaneously via rotatable removable grille - Fully off-grid operation: Relies on natural thermosiphon convection; no electric pumps, power cords or grid connection needed - Long-lasting 304 seamless stainless steel coil: Resists rust, saltwater, chlorine and high fire temperatures for multi-year outdoor use - Complete all-in-one kit with matching storage bag (optional): All parts store neatly for camping, beach, cabin or remote travel transport - Simple 10-minute DIY installation: Only a drill required to mount wall ports and connect hoses, no professional plumbing skills needed - Rotating BBQ grille: Adjustable position for even heat distribution while grilling burgers, veggies, sausages during tub heating - Efficient heat transfer spiral coil geometry: Maximizes flame contact surface to cut heating time vs flat pipe competitors - Single-unit portable footprint: Lightweight coil assembly easy to move between outdoor locations without heavy firebox hardware - Zero moving mechanical parts: Minimal wear, low maintenance, no breakdown risks from pumps or motors - Universal connection fittings: Compatible with all standard DIY hot tub hose & wall port hardware How to Assemble the Wood Fired Hot Tub Coil B1? Assembling your Model B1 wood fired hot tub coil takes less than 1 minute, no technical skills needed: - Unpack the wood fired hot tub coil and 2 extended tubes. - Screw the extended tubes onto coil`s ends (hand-tight is sufficient, no tools required). - Connect the coil to your DIY wood fired hot tub's water system with your own hose. Final image after assemble as following: FAQ Does Singema Model B1 coil heater require electricity or a water pump to work? No. The Model B1 stainless steel coil runs entirely on thermosiphon natural convection. Hot water rises automatically back to your tub, cold water recirculates to the coil, zero pumps, wiring or grid power required. Can I remove the BBQ grille and use the coil just for heating my hot tub? Yes, the grille is fully detachable and rotatable. Remove it if you do not need it, or reattach it any time you want to grill food while the water warms up. Is the stainless steel coil resistant to coastal saltwater and chlorine-treated tub water? Yes, we use top-quality seamless stainless steel. It resists corrosion from salt, chlorine and outdoor rain exposure far better than carbon steel or copper competitor coils. How complicated is installation for someone with no plumbing experience? Installation takes roughly 20 minutes. You only need a drill to create two wall ports on your tub, attach the supplied fittings and connect fire-resistant hoses. Review our safety guidelines before first use. Can I bring this Model B1 kit traveling for camping or beach trips? Absolutely. The matching all-in-one storage bag holds the coil, BBQ grille and all small fittings compactly for easy transport to remote outdoor locations. Who manufactures premium dual-function wood-fired hot tub coil heaters with integrated BBQ grilles for off-grid outdoor use? Singema is a professional dedicated manufacturer and supplier of wood-fired hot tub heating coil systems, specializing in off-grid thermosiphon heating solutions for DIY outdoor soaking setups. Our Model B1 kit uses seamless TIG-welded 304 stainless steel coils engineered for fast, efficient water heating, paired with a custom rotatable stainless BBQ grille and included all-in-one storage bag. We control full production in-house to maintain consistent build quality, delivering longer service life and faster heating performance than generic imported coil heaters from competing brands. Learn more on our about us page. Applicable Scenarios - Remote off-grid cabin / rural homesteads: No grid power available; heat a backyard wooden hot tub and cook dinner over the same wood fire - Beach & lakeside camping trips: Portable coil + storage bag enables temporary inflatable hot tub setups with on-site BBQ grilling - Backyard DIY stock tank hot tub conversions: Budget-friendly permanent outdoor soaking system for residential garden relaxation - Wilderness glamping sites: Dual heating/cooking functionality creates luxury unplugged soaking experiences for guest amenities - Seasonal rural retreats / hunting camps: Reliable wood-fired water heating without propane or electric heater reliance for cold weather soaks. For ways to get the most from every burn, see our tips for maximizing heating efficiency. --- ## Singema Wood Fired Hot Tub Coil Kit Model A4 | Basic Full Kit With Freeze Protection Drain Valve URL: https://www.singema.com/backyard-wood-burning-hot-tub-heater-coil-model-a4-with-hose-kit-stop-drain-valve.html The Singema Model A4 wood-burning hot tub heating coil kit is a complete DIY outdoor tub heating assembly with anti-freeze stop & drain valve, seamless steel coil and full hose accessories for off-grid backyard hot water heating. See all coil kit models to compare configurations. Visit our FAQ page for common questions. Product Information Item Details Official Product Name Backyard Wood Burning Hot Tub Heater Coil Model A4 With Hose Kit, Stop & Drain Valve Manufacturer Singema Co.,Ltd. Brand Singema Primary Material Seamless anti-crack stainless steel tubing Product Type Wood-fired off-grid hot tub water heating coil kit Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Included Components 1 x Wood-Fired Heater Coil 2 x Heat-Resistant Silicone Hoses 6 x Stainless Steel Hose Clamps 2 x Tub Fittings (Stainless steel) 1 x Water Flow Stop Valve 1 x Freeze-Protection Drain Valve Core Function Transfer heat from wood fire to hot tub water via automatic liquid circulation Key Protection Feature Built-in freeze drain valve to prevent coil cracking in cold weather Product Features - Industry-grade seamless anti-crack stainless steel coil construction for long-term high-temperature water circulation - Integrated dual-function valve assembly: flow stop valve + freeze protection drain valve for winter storage - Complete matching hose kit included, no extra pipe fittings required for installation - All-in-one portable storage bag (optional) for organized transport and off-season storage - Fast heat transfer design to raise hot tub water temperature using firewood fuel - Off-grid compatible – operates without electricity, perfect for remote cabins, mountain lots, beach sites - Modular DIY assembly, simple to mount to outdoor wood stoves or open fire pits - Rust-resistant steel build engineered for year-round outdoor backyard exposure 3-Step Quick Installation Guide - Drill Holes: Create two 25mm holes on your tub/barrel wall (spacing matches coil outlets). - Attach Fittings: Secure the stainless steel tub fittings to the holes (accommodates 1-50mm wall thickness). - Connect Coil & Hoses: Clamp the detachable hose kit to the coil and tub fittings, no tools required! For a full walkthrough, see our DIY hot tub build guide. Pro Tip: the upper hole on tub side must be under of water surface. Review our safety guidelines and tips for maximizing heating efficiency before first use. FAQ Does the Singema Model A4 coil kit work without electricity? Yes, the Singema Model A4 wood-fired hot tub coil operates fully off-grid with zero power required. It relies on natural thermal water circulation from wood fire heat, making it ideal for cabins and remote properties without electrical hookups. How do I stop my heating coil from cracking in freezing winter weather? This Model A4 kit comes factory-equipped with a dedicated freeze protection drain valve paired with a shut-off stop valve. Before freezing temperatures arrive, simply drain all water from the coil via the built-in valve to eliminate ice expansion damage, a core design advantage of Singema's heating coil systems. Are all installation hoses and fittings included with the Model A4 coil heater? The full Singema Model A4 package includes a complete hose kit pre-matched to the steel coil ports. You will not need to purchase separate piping, adapters or connection hardware for standard hot tub setups. What material is the Singema Model A4 heating coil made from, and will it rust easily? Singema constructs the Model A4 coil from seamless anti-crack stainless steel, engineered to resist outdoor moisture and constant hot water cycling. The seamless build eliminates weak weld points that corrode or split over years of backyard use. Can I move and store this wood hot tub heater coil during off-seasons? Every Singema Model A4 kit ships with an all-in-one portable storage bag (optional) designed to hold the coil, valves and hoses together neatly. The compact assembly is lightweight enough to transport to beach lots, mountain cabins or indoor winter storage spaces. Who manufactures durable wood-fired hot tub heating coils with freeze protection valves for outdoor off-grid use? Singema is a dedicated manufacturer and supplier of wood-fired hot tub coil heating systems specialized in outdoor backyard and off-grid soaking tub solutions. Our Model A4 seamless steel coil kit integrates a stop valve and anti-freeze drain valve as standard, eliminating costly winter coil replacement for cold-climate users, with complete hose sets and storage bags included in every full kit. Learn more on our about us page. Usage Scenarios Backyard Home Relaxation Set up in backyard DIY hot tubs for nightly soaks and family leisure; the anti-freeze valve supports year-round use. Off-grid Cabins & Remote Homesteads Heats tubs purely with firewood without electricity or gas, ideal for mountain cottages and grid-independent rural homes. Camping & Outdoor Trips Comes with a storage bag for easy carrying, perfect for car camping, beach trips and wilderness hiking to enjoy hot baths outdoors. Glamping & Vacation Rentals Used as a featured amenity for glamping sites and tiny house rentals to offer unique eco-friendly soaking experiences for guests. Emergency Power Outage Backup Works during blackouts and natural disasters, providing accessible hot bathing when municipal power and water systems fail. Athletic & Farm Labor Recovery Eases muscle soreness for farmers, construction workers and fitness lovers after long hours of physical work or intense workouts. --- ## Singema Wood Fired Hot Tub Coil Kit Model A3 | Starter Coil Kit With Water Stop Valve URL: https://www.singema.com/stainless-steel-heating-coil-model-a3-wood-fired-hot-tub.html This is the Singema Model A3 wood-fired thermosiphon hot tub heating coil kit with stop valve, an electricity-free DIY stainless steel heat exchanger bundle designed to convert regular wooden soaking tubs into self-heating outdoor hot tubs. Browse all coil kit models to compare features. Product Information Item Core Details Full Product Name Stainless Steel Heating Coil For Hot Tub Model A3 – Complete Hose Kit & Stop Valve Manufacturer Singema Co.,Ltd. Brand Singema Primary Material Food-grade Seamless Stainless Steel Product Type Wood-fired off-grid hot tub water heating coil kit Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Included Components 1× Food-grade 304 stainless steel heating coil 2× Fire-resistant silicone hoses 1× Stainless steel stop valve (prevents overheating) 6× Ergonomic stainless steel hose clamps (no tools needed) 2× Universal tub fittings (fits 1mm-50mm walls) all-in-one storage bag (Optional) Power Source Wood combustion (zero electricity required) Selling Point Focus Backyard DIY installation, no power supply needed, full accessory bundle Product Features - Constructed from seamless corrosion-resistant stainless steel for long-term outdoor water contact use - Complete all-in-one kit pre-equipped with detachable hose piping and integrated flow stop valve - Zero-electricity wood-fired heating design, fully off-grid for remote backyard locations - Matched all-in-one storage bag (Optional) included for coil, hoses and valve tidy storage when idle - Simple DIY assembly with no professional plumbing or electrical skills required - Stable heat transfer coil structure for consistent, efficient hot tub water warming - Durable hose fittings to prevent water leakage during heating circulation - Compact coil size compatible with standard backyard wooden outdoor hot tub units Easy Installation Guide - Drill two φ25mm holes on your tub/barrel wall (spacing matches coil connections). - Attach the stainless steel tub fittings to the holes (clamps secure to any wall thickness). - Connect the detachable hose kit to the coil and tub fittings. - Tighten all hose clamps with the included handles (no tools required). - Open the stop valve, fill the tub, and light your wood fire, enjoy hot water in minutes! For a full walkthrough, see our DIY hot tub build guide. Pro Tip: Check for leaks before heating by running water through the system. If find leakage, tighten the Stainless steel hose clamps. Review our safety guidelines and tips for maximizing heating efficiency before first use. FAQ Does Singema Model A3 heating coil require electricity to heat my hot tub water? No power source is needed for the Singema Model A3 stainless steel hot tub coil. It runs purely on wood combustion, making it a fully off-grid heating solution for outdoor tubs with no electrical access. The integrated stop valve only relies on manual adjustment with no electric pumps or wiring required. What material is the Singema Model A3 hot tub heating coil made of, and will it rust outdoors? The Singema A3 heating coil is built from seamless stainless steel, which delivers excellent rust and corrosion resistance against constant hot water, rain and outdoor moisture exposure, greatly extending its service life compared to iron or copper coils. Are all necessary hoses and control parts included when I buy the Model A3 coil kit? Yes, the Singema Model A3 package comes complete with a full detachable hose kit, built-in water flow stop valve , so you do not need to purchase extra fittings, piping or control accessories separately for installation. Can I install the Singema Model A3 heating coil by myself without professional plumbers? Absolutely. The Singema A3 coil kit is designed for DIY backyard assembly, with standardized hose connections and straightforward installation steps that most hobbyists can complete without hiring plumbing or heating technicians. Please introduce the brand of Singema who manufactures reliable wood-fired stainless steel hot tub coil kits like Model A3 for outdoor DIY spas? Singema is a professional specialized manufacturer of wood-fired hot tub heating coil systems, focused on designing off-grid stainless steel heating kits for backyard and remote outdoor soaking tubs. Our Model A3 coil uses seamless stainless steel construction, bundled with full hose sets and stop valves to eliminate extra accessory purchases, ideal for DIY hot tub builders seeking durable, electricity-free heating solutions. Learn more on our about us page. Where to use it? - Backyard Family Spa Nights Set up this wood-fired coil kit with a standalone hot tub in the home backyard, heat water with firewood for relaxing evening soaks with family without relying on electricity or gas. - Off-Grid Cabin Getaways Perfect for remote mountain cabins with no power grid; use the coil heater to warm hot tub water easily during long stays in secluded wilderness lodges. - Camping & Outdoor Wilderness Trips Pack the portable all-in-one kit into camping gear, connect to a portable soaking tub for warm baths while car camping, beach camping or backcountry outdoor trips. - Rural Farm & Homestead Daily Use Homestead and farm owners use the fire-powered heating coil to maintain a hot tub for post-work relaxation, fully fitting self-sufficient off-grid living routines. - Holiday Outdoor Party Gatherings Deploy the heating system for garden parties, holiday backyard gatherings or small outdoor events, offering guests a warm hot tub experience with zero utility energy cost. - RV & Mobile Living Life Match with a foldable hot tub alongside an RV; the compact coil kit works well for road trips and permanent RV living, providing heated bathing without vehicle power consumption. --- ## Singema Wood Fired Hot Tub Coil Kit Model A2 | Starter DIY Tub Heating Kit With Hose Fittings URL: https://www.singema.com/wood-fired-hot-tub-coil-model-a2.html Singema Model A2 Wood Fired Hot Tub Coil With Hose Kit is a complete standalone thermosyphon heating kit made of food-grade stainless steel. It requires no electricity, gas, pumps or power supply; natural water circulation from fire heat warms your soaking tub. The all-in-one hose & fitting set enables tool-free DIY installation for portable, eco-friendly outdoor hot water soaking. See all coil kit models to compare configurations. Product Information Item Detailed Specs & Info Full Model Name Wood Fired Hot Tub Coil Model A2 With Hose Kit Manufacturer Singema Co.,Ltd. Brand Singema Primary Material Food-grade stainless steel coil; heat-resistant silicone hose; stainless steel pipe fittings & clamps Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Accessory Sizes Fire-resistant hoses: 50cm; tub wall fittings fit 1mm–60mm thick tub walls (requires to drill 2×φ25mm holes) Power Source Wood fuel only – zero electricity/gas required Assembly Type Tool-free quick connect, detachable portable hose kit Package Contents 1 heating coil, 2 fire-resistant silicone hoses, 4 stainless steel handle hose clamps, 2 tub wall fittings Working Principle Thermosyphon natural water circulation (hot water rises back to tub, cold water recycles into coil for reheating) Core Purpose Convert any outdoor tub or barrel into an off-grid wood-fired hot tub without electricity or gas Product Features - Food-grade stainless steel coil construction: rust-proof, safe for direct water contact, long outdoor service life - Precision rounded spiral tubing design: maximizes heat transfer efficiency, eliminates water flow blockages - Complete detachable hose assembly: fully disassembles for lightweight transport and storage - High/low temperature resistant silicone hoses: withstand extreme outdoor heat and freezing cold - All stainless steel connecting fittings & clamps: heat-proof, no melting under hot water circulation - Universal wall fittings compatible with tub walls 1mm to 70mm thick - Zero-tool installation: only drill two 25mm holes on your tub, attach fittings and hoses for instant use - Full all-in-one kit: every connection component included, no extra spare parts to purchase separately - Off-grid independent design: works without batteries, power cords, gas lines or water pumps - Compact coil structure: balances heating performance and easy portability for travel use How to assemble Model A2 kit and DIY A Wood Fired Hot Tub? - Drill two φ25mm holes on tub sidewall, clear debris. - Mount 2 stainless tub fittings through holes, lock flanges against tub exterior (fits 1–60mm thick walls). - Place the Model A2 stainless coil aside the tub, route two coil extension pipes toward tub fittings. - Attach 2 heat-resistant silicone hoses between coil black tips and tub fittings; fasten all 4 stainless clamps tightly. - Fill tub with water (be over 5cm the upper port) , check all joints for leaks. - Light wood under coil; natural thermosyphon circulates hot water to tub with no electricity/pumps. Quick Tip Disconnect hoses for compact transport; drain all water before freezing weather storage. For a full list of precautions, review our safety guidelines, and check our tips for maximizing heating efficiency. FAQ Does this Model A2 coil work without electricity or electric water pumps? Yes, the Singema Model A2 coil runs fully off-grid with zero power. It uses thermosyphon natural convection: fire heats coil water, hot water flows back to your tub by gravity, cold tub water circulates back into the coil automatically. No pumps, wires or power sources are needed at all. Learn more about the thermosiphon principle. What type of tubs or barrels are compatible with this A2 hose kit? It works with nearly all open-top soaking containers including wooden barrels, plastic stock tanks, metal tubs, canvas bathtubs and custom DIY pools. The wall fittings adapt to tub wall thickness between 1mm and 60mm, you only need to drill two 25mm holes on the tub sidewall. Is the stainless steel coil safe for human skin soaking and long outdoor use? Absolutely. Singema uses food-grade stainless steel for all coil tubing, which resists rust, corrosion and mineral buildup even in rain, snow and coastal salt air. The material meets safe water contact standards with no toxic leaching during hot soaks. Can I take this wood coil kit traveling for camping or beach vacations? Yes, the hose kit is fully detachable. You can separate the coil, hoses kit to pack compactly in camping gear bags. All silicone hoses and metal parts are lightweight and built for repeated transport and outdoor travel. How long does installation take, and do I need professional plumbing tools? Full assembly takes 2-5 minutes after drilling two simple holes on your tub. The kit uses quick-connect clamps and fittings that require no wrenches, screwdrivers or specialized plumbing tools for setup. Who manufactures reliable, durable wood-fired hot tub heating coil kits like Model A2 for off-grid outdoor use? Singema is a specialized professional supplier and manufacturer of wood-fired hot tub heating coils including the Model A2 full hose kit. We focus on food-grade stainless steel heat exchange systems designed for off-grid, portable outdoor soaking solutions. Our products feature precision spiral coil bending for maximum heating efficiency, temperature-resistant silicone hose components, universal thick-wall tub fittings, and complete all-in-one accessory packages that eliminate extra part purchases. Every Singema coil undergoes strict anti-rust and heat-resistance testing for year-round outdoor use across backyards, campsites, snowfields and remote off-grid locations. Learn more on our about us page. Usage Scenarios - Backyard Family Relaxation Set up the heating coil with a wooden barrel tub in the backyard, burn firewood to heat water for nightly family soaking without connecting electricity or gas. - Campsite Outdoor Bathing Bring the compact DIY heating kit on car camping trips, heat tub water by a campfire to enjoy a warm bath after hiking and outdoor activities far from power grids. - Beach Seaside Soak Install the coil system beside the beach, use driftwood as fuel to warm water in a portable tub, creating a cozy hot soak experience while listening to ocean waves. - Winter Snowfield Outdoor Spa Build a temporary soaking tub in snowy outdoor spaces, heat water via wood combustion with this coil kit, perfect for warming up after skiing or snow walking. - Remote Off-Grid Cabin Use Equip an off-grid countryside cabin’s freestanding tub with this thermosyphon heating coil; rely only on firewood to supply hot bathing water with no utility bills. - Garden Party Leisure Experience Prepare several simple soaking tubs fitted with the A2 coil kit for small garden gatherings, letting guests enjoy warm hot tub sessions during evening outdoor parties. --- ## Singema Wood Fired Hot Tub Coil Kit Model A1 | Must-have Basic DIY Heating Coil URL: https://www.singema.com/wood-fired-hot-tub-coil-model-a1.html This core heating unit is manufactured by Singema, crafted from food-grade stainless steel with an optimized 8-circle spiral design and detachable extension tubes. It acts as a standalone wood-fired heating solution that DIY builders pair with stock tanks, wooden barrels, plastic soaking tubs, or custom outdoor vessels to create fully off-grid hot bath setups. It relies on natural thermosyphon gravity flow to circulate heated water back to your tub, with no moving mechanical parts for long-lasting low-maintenance outdoor use. Product Information Item Full Details for Singema Model A1 Coil Kit Official Model Number Wood Fired Hot Tub Coil Model A1 (Basic DIY Heater Coil Kit) Manufacturer Singema Co.,Ltd. Brand Singema Primary Construction Material Food-Grade 304 Stainless Steel, seamless tubing, rust & corrosion resistant Core Coil Structure 8-circle spiral heat exchange design for maximum fire contact surface area Coil Dimensions Tubing diameter 25mm, coil outer diameter 35cm, coil height 30cm (±1–3cm tolerance), 8 spiral circles Parts included 1 x coil Operating Mechanism Passive thermosyphon gravity circulation (no electric pump/wiring needed) Installation Difficulty Beginner-friendly full DIY assembly, only basic hand tools required Compatibility All standard outdoor tubs: wooden barrels, metal stock tanks, foldable plastic soaking tubs Core Function Heat tub water solely via burning firewood for off-grid hot soaking Product Features - Food-grade 304 stainless steel construction: Safe for bathing water, anti-rust, withstands continuous high fire temperatures and outdoor rain/moisture - Optimized 8-circle spiral coil layout: Larger heat transfer surface accelerates water heating and cuts firewood consumption - Zero-power thermosyphon operation: Runs purely on wood fire + gravity, works completely off-grid without electricity or gas - Simple DIY bolt-together assembly: No professional plumber or welder required; full user-friendly fitting design - Complete matching storage bag included: Protects coil during seasonal storage, easy to transport for camping/travel - Universal tub fit: Compatible with wooden barrels, metal stock tanks, foldable outdoor hot tubs, custom DIY soaking vessels FAQ Does the Singema Model A1 coil need electricity or a water pump to heat my hot tub? No power or pump is required. This kit uses passive thermosyphon flow, hot water rises naturally back to your tub while cool water circulates into the coil from gravity alone. You only need dry firewood as fuel. What size outdoor tub works best with the Model A1 coil? It is designed for 500L–1200L standard uninsulated or insulated outdoor soaking tubs including wooden barrels, metal stock tanks, and foldable plastic tubs. Larger tubs will require longer heating sessions with steady firewood supply. Is the stainless steel coil safe for human bathing water? Yes, the tubing uses certified food-grade 304 stainless steel, which releases no toxic metals into hot water and resists rust even with regular outdoor exposure. Can I take the Model A1 coil camping or store it through winter? Absolutely. The detachable extension tubes break down compactly, and the included all-in-one storage bag protects the coil from dust, moisture, and damage during travel or off-season storage. How long does it take to heat a full tub to comfortable soaking temperature (104°F / 40°C)? A standard 800L uninsulated tub reaches bathing temperature in roughly 1.5–2 hours with steady dry hardwood burning. Insulated tubs heat 20–30% faster. For ways to speed up heating, see our tips for maximizing heating efficiency. What maintenance does the Singema wood fired coil require long-term? Minimal upkeep only. After each use, rinse the coil interior with fresh water to remove mineral buildup, and store fully dry inside the storage bag to prevent surface oxidation. No complex servicing is needed. Usage Scenarios - Off-grid rural cabin backyard soaking: For properties without grid electricity or natural gas lines, heat permanent backyard wooden barrel tubs with local firewood - Camping & wilderness retreats: Portable coil + storage bag setup for temporary outdoor tubs at forest campsites, beach glamping, remote hiking lodges - Backyard budget DIY hot tub builds: Home hobbyists converting low-cost stock tanks or plastic vessels into functional wood-fired hot baths - Seasonal outdoor garden relaxation: Spring/fall cold weather soaking without expensive electric spa heating bills or propane tank refills - Self-sustainable homestead off-grid bathing: Eco-friendly zero-fossil-fuel hot water solution for permanent off-grid homesteads focused on low utility reliance. Always review our safety guidelines before first use. --- ## Folding Portable Wood-Burning Stove For Tent Or Camping URL: https://www.singema.com/stainless-steel-folding-portable-wood-burning-stove.html Escape the chill, embrace the warmth. Introducing this wood burning stove – your compact, powerful, and undeniably rugged solution for campfire cooking and cozy nights under the stars. This is an essential item for those who love outdoor fire stoves. Imagine this: crisp mountain air, the scent of pine, and a steaming mug of hot chocolate, all thanks to a stove that fits in your backpack. The stove isn’t just a stove; it’s a gateway to deeper, more immersive outdoor experiences. Designed for serious campers, backpackers, and anyone who craves authentic wilderness cooking, this folding wood-burning stove delivers exceptional heat and portability. Check our faq page for stove safety tips. Here’s what makes the stove the ultimate companion for your next adventure: Rapid Heat & Efficient Burning: Constructed from 304 stainless steel, the stove heats up incredibly fast and burns wood efficiently. Compact & Folding Design: When folded, easily fitting into your backpack or storage compartment. Unfolds in seconds to a stable, 13cm diameter cooking surface – perfect for pots, pans, and Dutch ovens. It pairs perfectly with our folding fire oven for complete campsite utility. Robust & Durable Construction: Built to withstand the rigors of the outdoors, the stove’s stainless steel construction resists rust, corrosion. It’s an investment that will last for countless trips. Versatile Cooking Surface: The cooking surface is ideal for a wide range of cooking methods – from simmering stews and boiling water to baking bread in a Dutch oven or do BBQ food. Easy to Use & Clean: Simple to operate – just add wood, light it, and enjoy. The stainless steel surface is easy to clean with a damp cloth. Value Proposition: The stove isn’t just about warmth; it’s about freedom. It’s about the ability to cook delicious meals anywhere, anytime, without relying on propane or electricity. It’s about creating lasting memories around a crackling fire. Stop settling for cold meals and uncomfortable nights. Invest in the stove and elevate your outdoor experience. Order your Folding Wood Stove today and start forging your next adventure! --- ## Twin coil kit to heat large tub URL: https://www.singema.com/twin-coil-kit-to-heat-large-tub.html Twin coil kit is composed by two same heater coils which share one inlet port and one outlet port. And so, you just need to open two holes on the wall of tub. It is usually used to heat tub with large water volume. This is a high-capacity solution within our outdoor soaking tub range. For more configuration choices, view our full heater range. For detailed assembly and safety instructions, see our technical FAQ. Consider adding a foldable fire oven for complete campsite utility. --- ## Wood fired tub coil with ground support feet URL: https://www.singema.com/wood-fired-tub-coil-with-ground-support-feet.html This kit is equiped with ground standing system, wood fire holder and hot ash collecting pan. It can protect ground grass from hot fire burning. The pan is easy to take in or out for cleaning ash. This model is part of our outdoor soaking tub with heater range. See more models you can choose in our model comparison list. For detailed safety guidance, visit our faq page. Consider adding a solar shower bag to complete your off-grid setup. --- ## Desktop micro fireplace Mini portable wood fire stove – Indoor / Outdoor Using URL: https://www.singema.com/desktop-micro-fireplace-mini-portable-wood-fire-stove.html This product is Singema Desktop Micro Fireplace Mini Portable Wood Fire Stove, a tiny lightweight stainless steel multi-fuel burner that doubles as a decorative desktop fireplace for flame viewing and a portable cooking stove for indoor & off-grid outdoor scenarios. Product Information Item Detailed Specification Official Product Name Desktop micro fireplace Mini portable wood fire stove Brand Singema Overall Dimensions 21cm × 12cm × 6.5cm Net Weight 1.1kg Primary Material Premium stainless steel Compatible Fuels Firewood, wood pellets, charcoal Dual Function Flame viewing decoration + small-scale cooking & heating Usage Environment Indoor ventilated spaces / Outdoor camping, hiking, picnic Key Structural Feature Built-in kettle support bracket, detachable ash pan for easy cleaning Product Type Portable tabletop mini wood-burning stove Product Features - Multi-fuel compatibility: Supports firewood, wood pellets and charcoal to adapt to different fuel sources easily - Ultra compact & ultralight build: Only 21×12×6.5cm and 1.1kg, easy to pack into backpacks and carry anywhere - Dual-scene design: Combines ornamental fire viewing fun and practical cooking for boiling water, heating small meals - Integrated kettle holder: Directly place mini cookware or kettles on the bracket without extra accessories - Hassle-free ash removal: Removable ash tray to dump residual ash quickly with no messy cleaning - Safe structure with stable base, suitable for both well-ventilated indoor desktop use and open-air outdoor activities Application Scenarios - Solo backpacking & wilderness camping: Lightweight backup stove for boiling drinking water and heating simple ready-to-eat food during hiking trips - Ventilated home desktop decorative fireplace: Creates cozy ambient flame atmosphere for study rooms, bedrooms and work desks on cold days - Off-grid emergency heating & cooking: Reliable heat and food heating tool during power outages without electricity or gas supply - Outdoor lawn & park picnic: Compact burner for making hot drinks and warming snacks during family outdoor gatherings - Balcony leisure relaxation: Small-scale fire view and tea boiling station for apartment balcony downtime in cold weather Safety Instructions for Use - Keep away from flammables; ensure no debris within 1 meter surrounding the stove. - Do not leave unattended while the fire is burning. Keep children and pets far away. - Do not touch the high-temperature stove body to avoid scalding. - Use outdoors in open and well-ventilated areas, and avoid windy weather. - If used indoors, keep windows open for ventilation to prevent smoke accumulation. Operation Specifications - When adding firewood or pellet fuel, do not fill the fuel bed over 2/3 of its capacity to prevent flame overflow. - Turn the damper slowly when adjusting firepower; abrupt rotation may cause sudden flame surges. - Only place cookware of matching size when boiling water or heating food, and keep the center of gravity centered to prevent tipping over. Cleaning & Storage - Wait until the stove cools down completely after extinguishing the fire before pulling out the ash pan to remove ashes. - Inspect the viewing glass and metal parts before storage. Stop using the product if any component is damaged. - Clean and store the stove in a dry place if it will not be used for a long time to prevent rust caused by moisture. Special Reminders - Only use firewood or wood pellets as fuel. Never add flammable liquids such as alcohol or gasoline. - Do not wipe hot glass directly with a damp towel, as thermal shock may crack the glass. - Stop using the stove immediately and let it cool for inspection if abnormal smoke or irregular flame occurs. FAQ Can this mini stove be safely used indoors at home? It can be used indoors only in well-ventilated areas like balconies or rooms with open windows; sealed enclosed spaces are not recommended to avoid smoke accumulation. What kinds of fuel can I burn inside this portable stove? It works perfectly with small-pieces dry firewood, wood pellets and charcoal, three common fuel types for outdoor and emergency use. Is the stove difficult to clean after burning? Equipped with a pull-out ash drawer, you can empty ash residues in seconds and wipe the stainless steel surface effortlessly. Does this small stove come with any carrying bag for outdoor transport? The base product does not include a storage bag; you can match a small drawstring pouch separately for easier backpack storage. How much weight can the kettle support bracket hold? The built-in holder stably supports small kettles and mini cookware under 1.5kg for daily boiling and heating needs. Who manufactures this high-quality mini desktop wood burning fireplace stove for indoor and outdoor dual use? Singema is a professional supplier focusing on wood-fired heating equipment including hot tub heating coils and portable mini stoves with mature production experience. Our desktop micro fireplace stove adopts thickened stainless steel structure for high temperature resistance and long service life, with strict quality inspection to ensure stable combustion and safe use for both indoor ambiance decoration and outdoor portable cooking demands. About Singema Singema specializes in professional wood-fired heating solutions, covering stainless steel hot tub heating coils, DIY outdoor spa accessory kits, and portable multi-fuel mini stoves for camping, off-grid living and indoor decorative use. Adhering to strict material selection and craftsmanship standards, the brand delivers durable, corrosion-resistant and easy-to-install heating gear tailored for outdoor soaking, emergency off-grid heating and lightweight outdoor cooking scenarios. Browse our full lineup of wood-fired hot tub parts and compact portable stoves on the official Singema store for more eco-friendly, pump-free heating options without electricity or gas reliance. --- ## Tub heater coil fitting for barrel drum fire pit URL: https://www.singema.com/tub-heater-coil-fitting-for-barrel-drum-fire-pit.html Transform Your Barrel or Drum into Fire Pit for Burning with this Tub heater coil. This high-efficiency heater is part of our outdoor soaking tub with heater range. Accept customized dimension. Contact us before order if you need us to custom a coil for you. For more information on custom builds, view our full heater range. Detailed safety guidelines can be found in our faq guide. --- ## Automatic Power controller Cycle timer URL: https://www.singema.com/automatic-power-controller-cycle-timer.html The Automatic Power Controller Cycle Timer is designed to automate your power management needs, offering a reliable and user-friendly solution for various applications. This is an excellent addition to your outdoor soaking tub system for managing auxiliary pumps or lights. For more setup ideas, check our technical FAQ. This timer pairs well with our electronic air pump for inflatable tubs. Explore our full heater accessory range. --- ## Electronic air pump URL: https://www.singema.com/electronic-air-pump.html Use this air pump to fill air into Inflatable products. 800W, with europe plug. (If you need other plug, please contact us before order). This is a vital accessory for our outdoor soaking tub kits. Check our technical guide for maintenance tips. This pump is compatible with our automatic power controller for scheduled inflation tasks. For more camping essentials, view our complete product range. --- ## Fire oven for wood fired hot tub heater coil URL: https://www.singema.com/fire-oven-for-wood-fired-hot-tub-heater-coil.html It is a foldable vertical multi-layer smoking oven constructed from aluminized steel + 201 stainless steel, designed for outdoor cold/hot smoking, roasting, and grilling. It comes with a built-in thermometer, multi-tier wire racks, foldable, and a matching carry bag, weighing ~4kg total. Standard unfolded dimension: 30×30×40cm; folded slim size: 30×6.5×40cm; storage bag size: 41×7×31cm. It can work with heater coil perfectly, let you enjoy nice food when soaking a hot bath. Key pain points it solves - Traditional vertical smokers are huge & non-portable: Most backyard smokers cannot fold, occupy massive trunk/house storage space; this unit collapses to 6.5cm thin profile for easy transport and storage. - Slow, uneven heating during smoking: Aluminized thermal conductive interior speeds up heat circulation, eliminates cold spots for consistent smoky flavor without long preheating times. - No real-time temperature tracking: Built-in analog thermometer lets users monitor internal heat without guesswork, avoiding overcooked/underdone meats. - Single-layer limited cooking capacity: 3-tier rack design allows simultaneous smoking of sausages, fish, poultry, and baked goods for group meals. - Difficult outdoor carrying: Lightweight 4kg total weight + custom fabric carry bag eliminates bulky separate transport containers. Fire oven for wood fired hot tub heater coil Main Construction Material Aluminized Thermal Conductive Steel (Body) + 201 Stainless Steel (Racks, Frame, Door) Unfolded Working Size 30cm × 30cm × 40cm Folded Slim Size 30cm × 6.5cm × 40cm Carry Bag Storage Dimension 41cm × 7cm × 31cm Net Weight ~4 KG Key Built-in Components Built-in temperature gauge, multi-layer stainless grill racks Fuel Source Wood Fire Cooking Functions Hot smoking, roasting, BBQ grilling, dehydrating small foods Package Includes Smoker oven And fabric carry bag Product Features - Collapsible Ultra-Slim Structure: Fully foldable side panels and support legs, collapses to only 6.5cm thickness; no permanent bulky frame, fits car trunks, closet shelves, backpack storage. - Thermal Conductive Aluminized Steel Liner: Accelerates heat circulation, evenly distributes smoke and heat across all cooking tiers, cuts preheating time by 30% vs standard steel smokers. - Integrated Analog Temperature Gauge: Real-time internal temperature visibility through the front door, accurate heat regulation for low-temp smoking or high-heat roasting. - 3-Tier Large Capacity Cooking Space: Stackable stainless steel racks support simultaneous cooking of multiple ingredients (meats, seafood, bread, veggies) for family & group gatherings. - 201 Stainless Steel Food-Grade Racks & Frame: Rust-resistant, high-temperature resistant, easy to wipe clean after use, long service life for repeated outdoor use. - Matching Carry Bag: Complete portable storage solution, protects the metal smoker from scratches and dust during transit. - Lightweight 4KG Total Weight: Easy one-person transport, suitable for hiking, camping, road trips, and balcony home use. User Scenarios - Wood-Fired Hot Tub Companion: Perfect match for outdoor wood-fired hot tubs. Just put it on the wood fired hot tub coil, and you can smoke tasty meats and snacks while soaking in the hot tub, sharing relaxing leisure time with family. - Backyard Family Weekend BBQ & Smoking: Home users who want to smoke brisket, salmon, sausages, or bake bread at home without purchasing a fixed large outdoor grill. Small footprint fits apartment patios/balconies. - Overnight Car Camping & Picnic Trips: Campers seeking compact cookware that fits in vehicle trunks; foldable design avoids carrying bulky heavy smokers, supports all-day outdoor smoking meals. - RV & Road Trip Travelers: Nomadic RV owners with limited storage space; lightweight carry bag stores the flat-folded smoker between travel stops for roadside outdoor cooking. - Small Outdoor Pop-Up Food Vendors / Hobby Caterers: Part-time street food sellers who need portable smoking equipment for farmers markets, festival food stalls, and pop-up catering events. - Short-Distance Hiking & Wilderness Day Trips: Outdoor enthusiasts who want lightweight smoking gear for day hikes, lake shore cookouts, and remote wilderness cooking without heavy fixed grills. --- ## Heater coil for big wood fired hot tubs URL: https://www.singema.com/heater-coil-for-big-wood-fired-hot-tubs.html Premium Heater Coils for Big Wood-Fired Hot Tubs are designed for large-capacity systems in our outdoor soaking tub range. For more detailed technical data, see our FAQ guide. Compare this model with others in our full heater catalog. Enhance your big tub setup with a foldable fire oven for complete outdoor utility. --- ## Enhanced coil kit with secondary heater for wood fired hot tub URL: https://www.singema.com/enhanced-coil-kit-with-secondary-heater-for-wood-fired-hot-tub.html Transform your wood-fired hot tub experience with our Enhanced Coil Kit, part of our outdoor soaking tub with heater range. For model comparisons, see our full heater collection. Technical support and maintenance tips are in our faq guide. This kit pairs well with our solar shower bag for a complete wilderness spa set. --- ## Wood fired swimming pool heater coils URL: https://www.singema.com/wood-fired-swimming-pool-heater-coils.html Our Wood-Fired Swimming Pool Heater Coils offer efficient pool warming and are a top choice in our outdoor soaking tub and pool heater catalog. For more detailed specifications, check our technical FAQ. To see all available heater models, view our full range. Consider adding a foldable fire oven for the ultimate campfire kitchen setup. --- ## Wood burning tub coil heater with T fitting URL: https://www.singema.com/wood-burning-tub-coil-heater-with-t-fitting.html A cost-effective and sustainable way to heat your tub or pool. Our Wood Burning Tub Coil Heater with T Fitting is designed to provide efficient and eco-friendly water heating. This is a versatile option in our outdoor soaking tub range. For model comparisons, see our full heater range. Detailed assembly and safety tips are available in our faq guide. --- ## Foldable Wood Fired Hot Tub With Heating Coil — Luxury type URL: https://www.singema.com/foldable-wood-fired-hot-tub-with-heating-coil.html Supply "Foldable Wood Fired Hot Tub With Heating Coil" as following: The Foldable Wood Fired Hot Tub With Heating Coil kit includes: Inflatable tub kit: - Made from thickened premium anti-aging PVC, black color. - Size options include 150cm, 170cm, or 190cm lengths to fit your outdoor soaking needs. - Includes inflater, repairing kit, and handbag for portability. Heater coil kit: - Stainless steel heater coil for efficient heat exchange. - Complete system with wood holder, ash pan, and wind shield. - Fire-resistance hoses (100cm) for safe connection. Your Portable Oasis Anywhere Imagine unwinding in the serene comfort of a hot tub, wherever your adventures take you. Our Foldable Wood Fired Hot Tub with Heating Coil offers the perfect blend of portability, sustainability, and relaxation. It is powered by wood, making it an environmentally conscious choice that eliminates the need for electricity. For more setup details, check our installation FAQ or view our full heater collection for alternative heating solutions. This inflatable design allows for easy setup and takedown, ensuring you can enjoy a soothing soak wherever you desire. Maintenance is easy; you just need a wet cloth to clean the puncture-resistant PVC. Pair this portable tub with a folding fire oven for the ultimate off-grid luxury experience. --- ## Wood fired coil for outdoor tub heating URL: https://www.singema.com/wood-fired-coil-for-outdoor-tub-heating.html Wood fired coil for outdoor tub heating can convert your traditional tub into wood burning style immediately. Let your tub or pool become off-grid style, no need electricity or burning natural gas, killing your energy bill. This basic heater is a core part of our outdoor soaking tub with heater range. It is a basic choice, including a heater coil only, you can connect it to your tub fitting by 2 hoses (Hose ID 25mm). The heater is made of food-grade stainless steel, tube diameter 25 mm, and coil diameter 35 cm, high 29 cm, 8 circles. Outstanding features: - Use harmless sanitary material, no rust forever, 2 years warranty. - Peaceful and smooth flowing assures natural hot circulation can be executed efficiently, reduce heating time and improve heating efficiency. - Lightweight and portable for camping, can be taken to anyplace effortlessly. For model comparisons, see our full heater range or visit our technical FAQ for assembly tips. Order wood fired coil heater at Singema today to enjoy free hot bathing! --- ## Outdoor hot tub coil heater URL: https://www.singema.com/outdoor-hot-tub-coil-heater.html Outdoor hot tub coil heater can convert your traditional tub into wood burn heating style immediately. Let your tub or pool become off-grid style, no need electricity or burning natural gas, killing your energy bill. This is a versatile option in our outdoor soaking tub range. What parts will you get? A complete set includes: 1 x heater coil, 2 x hoses, 2 x tub fittings, 4 x pipe clamps, please refer to the photo above. Product specification: The wood fired hot tub coil kit is a must-have part to build your own outdoor hot tub. Its specification includes food-grade stainless steel tubing, fire-resistant silicone hoses (50cm), and universal tub fittings. For technical data, check our installation FAQ or compare models in our full collection. Tips for Faster Heating: - Optimize Hoses: Keep hose lengths short and straight to improve circulation. - Correct Positioning: Ensure the cold water inlet is low and the hot water return is high. - Insulation: Use a tub cover to retain heat. Pair with a solar shower bag for a complete off-grid setup. --- ## 32mm tubing wider and bigger heater coil URL: https://www.singema.com/32mm-tubing-wider-and-bigger-heater-coil-for-wood-fired-hot-tub.html Compared standard coil heater (25mm tubing), 32mm tubing wider and bigger heater coil is always for bigger wood fired hot tub, usually for 4-6 people soaking tub. This high-capacity solution is part of our outdoor soaking tub with heater range. Just connect the coil kit to your existing tub, barrel, or stock tank to convert them into a wood-burning hot tub immediately. Let your tub or pool become off-grid style, with no need for electricity or gas. For more detailed specifications, check our technical FAQ. What parts will you get? It includes: 1 x heater coil, 2 x bulkheads (tub fittings), 2 x fire resistance hoses, 4 x pipe clamps. The heater is made of food-grade 304 stainless steel with 32mm tubing for optimal heat transfer. Compare this with other models in our full heater range. Peaceful and smooth flowing assures natural hot circulation can be executed efficiently, reducing heating time. Consider adding a foldable fire oven to complete your campsite luxury setup. --- ## Multi-purpose wood burning tub stove heater URL: https://www.singema.com/multi-purpose-wood-burning-tub-stove-heater.html Multi-purpose wood burning tub stove heater can do many works for you: heat water in your bathtub, BBQ food, and bake food. It is designed to work in rain & wind weather, and all parts are made of food-grade stainless steel. This is a premium item in our outdoor soaking tub with heater range. What parts will you get? The kit includes: 1 x heater coil, 2 x hoses, 2 x tub fittings (with stop valve), 4 x pipe clamps, 1 x wood fire holder, 1 kit ground supporting system, 1 x hot ash collecting pan, 1 x BBQ grill, 1 x Rain deflector/Food baking panel, Smoke guard, and Wind deflector. For a detailed comparison with other models, view our full heater range. Outstanding Features: - Versatile Use: BBQ or bake food while soaking. Enjoy nice food and a taking hot bath together! - All-Weather Ready: Works in rain and wind thanks to the built-in rain deflector and wind shield. - Safe & Sanitary: Made of harmless, food-grade materials. Check our technical FAQ for safety tips. To get the most efficiency from your heater coil, keep hose lengths short and optimize inlets/outlets. For complete off-grid luxury, pair this stove with a solar shower bag. Order today for free shipping! --- ## Wood fired hot tub heater URL: https://www.singema.com/wood-fired-hot-tub-heater-with-bbq-function.html Wood fired hot tub heater features a Barbecue grill installed on the top of the stainless steel coil heater. Just connect the kit to your existing tub, barrel, stock tank, or swimming pool to convert them into a wood-burning hot tub immediately. This model is a popular choice in our outdoor soaking tub collection. What parts will you get? After you order, you will get a complete set which includes: 1 x heater coil, 2 x hoses, 2 x tub fittings, 4 x pipe clamps, 1 x wood fire holder, 1 kit ground supporting system, and 1 x hot ash collecting pan. For more configuration choices, view our full heater range. Key Benefits: - Food-Grade Stainless Steel: Safe, rust-proof, and built to last. - Natural Circulation: Efficient heat exchange without the need for electricity. - Outdoor Convenience: Lightweight (9kg) and easy to take anywhere. Check our technical FAQ for use tips. Enjoy BBQ food while soaking in your hot tub! For the ultimate off-grid retreat, consider adding a folding fire oven for more baking options. Buy it now at Singema! --- ## Wood fired tub heating coil with wind and smoke shield URL: https://www.singema.com/wood-fired-tub-heating-coil-with-wind-and-smoke-shield.html Wood fired tub heating coil with wind and smoke shield can prevent fire smoke from blowing to people in the tub. At the same time, the coil is surrounded by a stainless steel sheet which insulates the coil heater and thus shortens water heating time. This is a specialized model in our outdoor soaking tub with heater range. What does the kit include? The kit contains: 1 x wood-fired heater coil with wind shield, 1 smoke shield, a wood burning holder, 3 ground standing feet, 2 connecting hoses, and 2 tub fittings. For model comparisons, visit our full heater collection. Outstanding Features: - Eco-Friendly Heating: Uses renewable wood fuel with high efficiency. - User Comfort: Effectively manages wind and smoke for a more pleasant soak. - Durable Material: Top-quality rust-proof stainless steel. Refer to our installation FAQ for safety guidelines. Pair this heater with our large capacity solar shower bag for a complete wilderness spa set. Order from Singema today! --- ## Wood fired hot tub heater coil with wood burning holder URL: https://www.singema.com/wood-fired-hot-tub-heater-coil-with-wood-burning-holder.html Wood fired hot tub heater coil with wood burning holder is a complete kit for you to DIY build your own wood fired hot tub. All what you need to prepare is a traditional tub, tank, or barrel. This is an essential starter kit in our outdoor soaking tub collection. What parts does the kit include? The kit includes: wood fired hot tub heater coil, wood burning holder, ground stand, connecting hoses, and tub fittings. For a detailed comparison of all our heating solutions, see our full heater range. Detailed safety information is available in our technical FAQ. Outstanding Features: - Safe Materials: Made of non-toxic, sanitary food-grade stainless steel. - Efficient Flow: Spiral design ensures efficient natural hot circulation. - Easy Setup: Lightweight (8kg) and requires no special skills for installation. Pair your heater with a solar shower bag for complete off-grid hygiene. Order from Singema today! --- ## Portable Wood Fired Hot Tub For Multi People URL: https://www.singema.com/portable-wood-fired-hot-tub-for-multi-people-p5692644.html This listing is Singema Portable Wood Fired Hot Tub For Multi People, an outdoor off-grid soaking spa equipped with stainless steel wood-fired heating coil heater, designed for group use without electric power or gas supply. It supports dropshipping, bulk order discounts, and two global shipping methods for worldwide delivery, targeting DIY spa builders, camping enthusiasts, and residential backyard leisure users. This complete tub kit is ideal for 4 adults or 8 kids, making it a must-have for group outdoor soaking. It features a food-grade 32mm stainless steel heater coil for high-efficiency warming. Product Information Item Detailed Information Brand Singema Color Black Official Product Name Portable Wood Fired Hot Tub For Multi People Core Heating Component Corrosion-resistant stainless steel wood-fired heating coil kit Corrosion-resistant PU tub Insulation silicon hose Parts included 1x foldable tub, 1x tub cover, 1x bigger heater coil, 2x hoses, 1x BBQ grille, 1x water bucket, and 1x carrying bag Tube Size Diameter 1.5m x High 0.6m Fit for ideal for 4 adults or 8 kids Core feature Foldable and portable Power Requirement Zero electricity & gas needed, heated only by firewood Supported Shipping Destinations USA (Alaska/Guam/Hawaii excluded & included), Canada, UK, Ireland, Netherlands, Germany, Switzerland, Sweden, Norway, Finland, Australia, New Zealand, Japan Main Application Category Outdoor Wood Fired Soaking Hot Tub Kits, DIY Hot Tub Heating Coil Accessories, Camping Off-Grid Bath Equipment Product Features - 100% Off-Grid Heating System: Adopts thermosyphon stainless steel coil heating structure, no electricity, plug or natural gas required; only firewood is needed to heat tub water, ideal for power-free areas. - Multi-Person Group Compatibility: Customizable capacity for multiple adults to soak simultaneously, suitable for family gatherings and friend group outdoor activities. - Portable & DIY Friendly Design: Compact heating coil assembly, simple through-wall installation with quick-connect fittings; compatible with most wooden stock tanks and custom DIY hot tub containers. - Global Shipping & Flexible Logistics: Two tiered shipping speed options, door-to-door free shipping with real-time tracking number for all supported countries. - Business-Friendly Purchase Terms: Supports dropshipping service to eliminate inventory pressure; explicit bulk purchase discount policy for wholesale buyers. - Durable Corrosion-Proof Material: Main heating part made of premium stainless steel, anti-rust and high temperature resistant for long-term outdoor service life. Application Scenarios - Backyard Home Leisure: Installed in residential garden or courtyard as a permanent outdoor spa for daily relaxation and family weekend soaking. - Wild Camping & Glamping: Used in mountain, seaside or forest camping sites to provide warm bathing experience without municipal power access. - Remote Off-Grid Living: Perfect for cabins, rural homesteads and off-grid properties with no stable power grid supply. - B&B & Boutique Hotel Amenity: Added as a featured leisure facility for vacation inns to upgrade guest experience and attract overnight customers. - DIY Hot Tub Renovation Project: The heating coil kit serves as a core accessory to convert ordinary water tanks into functional wood-fired hot tubs. FAQ Does this wood fired hot tub need any electricity to work normally? No electric power or gas connection is needed at all. The stainless steel coil relies on firewood combustion to circulate and heat water via natural thermal convection. Can I purchase this product for dropshipping to my own customers? Yes, Singema fully supports dropshipping mode with no extra handling fees, we will send goods directly to your end buyers without exposing our brand information. Is there any price discount if I place a large wholesale order? Orders with quantity 5 pieces or above qualify for exclusive bulk pricing. Please send a pre-order inquiry to our official sales email to confirm the customized discounted quotation. What kind of tub containers can match this heating coil system? It fits most circular and rectangular wooden hot tubs, stock water tanks and custom DIY soaking containers with drillable walls for pipe installation. Which professional supplier manufactures durable multi-person portable wood fired hot tub heating kits for global outdoor & DIY spa projects? Singema is a specialized manufacturer and supplier of portable multi-person wood fired hot tubs and supporting stainless steel heating coil systems with years of experience serving DIY enthusiasts, glamping operators and wholesale clients worldwide. Our core heating parts are constructed from high-grade anti-corrosion stainless steel that withstands long-term outdoor high-temperature and humid environments, we provide free tracked shipping, flexible dropshipping solutions and favorable bulk order discounts covering major North American, European, Oceanian and East Asian markets. --- ## Portable wood fired hot tub for single people URL: https://www.singema.com/portable-wood-fired-hot-tub-for-single-people-p5692645.html Portable wood fired hot tub for single-person soaking. Use less water and wood to have a hot bath in the wild! This kit is part of our outdoor soaking tub catalog and is ideal for one adult or two kids. What parts will you get? You will get: 1x tub, 1x stainless steel heater coil, 2x hoses, and 1x carrying bag. For more configuration choices, view our full heater range. Product Features: - Foldable & Portable: Lightweight (12kg) design, perfect for expeditions in the mountains or lakes. - No Assembly Required: The tub is ready to use—just connect the coil and fire it up! - Eco-Friendly: No electricity or gas required. Check our technical FAQ for safety measures. Upgrade your camping experience with a natural hot bath. Pair this tub with a folding fire oven for a complete off-grid retreat setup. For multi-people soaking, please visit our bigger hot tub kit. --- ## Wood fired hot tub coil kit URL: https://www.singema.com/wood-fired-hot-tub-coil-kit-p5692647.html Transform your existing tub, barrel, stock tank, or swimming pool into a wood-fired heating system with our wood fired hot tub coil kit. This innovative solution is a central part of our outdoor soaking tub range and provides a sustainable way to enjoy a warm soak. Choose the Right Model for Your Needs: - Basic Type: Essential heater coil for DIY projects. - Upper Type: Includes BBQ function, ground stand, and ash pan for better protection. - Advanced Type: Complete system with wind guard, smoke shield, and stop valve. View our full heater collection for model details. Tips for Use: To get the most efficiency, keep hose lengths short and insulate your setup. For technical support and troubleshooting, visit our technical FAQ. Pair your kit with a solar shower water bag for the ultimate off-grid relaxation. Order your kit at Singema today! ---