How Wood Fired Hot Tubs Work
A wood fired hot tub heats water using a wood-burning stove instead of an electric heater. There's no electricity involved, no plumbing hookup, and no gas line. You fill the tub with a garden hose, build a fire in the stove, and wait for the water to come up to temperature. It's about as simple as outdoor soaking gets.
There are two main stove designs. An internal (submersible) stove sits inside the tub, separated from bathers by a wooden fence or metal guard. Water surrounds the firebox directly, so heat transfer is fast and efficient. An external stove sits outside the tub and connects through inlet and outlet ports. As water heats inside the stove, it naturally rises and circulates back into the tub through a process called thermosiphoning, with no pump needed. External stoves free up soaking space inside the tub, though they typically take longer to reach temperature.
Most wood fired tubs reach a comfortable 100–105°F in 90 minutes to 3 hours, depending on tub size, stove type, water temperature, and how cold it is outside. Smaller tubs with submersible stoves heat fastest. Larger tubs with external stoves sit on the longer end of that range.
How to Choose the Right Wood Fired Hot Tub
Construction materials matter
The tub's material affects durability, maintenance, and how long it'll last. The Dundalk Starlight comes with your choice of an aluminum interior or a white plastic interior. Both are leak-proof and easier to clean than an all-wood interior. Aluminum liners resist corrosion and last decades with minimal upkeep. The SaunaLife S4 uses Scandinavian spruce construction in either a natural or black finish, giving it a clean barrel aesthetic that looks right at home next to an outdoor sauna.
Capacity and who's soaking
Think about how you'll actually use the tub. The Dundalk Starlight is a rectangular soaking tub built from Eastern White Cedar, and it fits comfortably for one person. The SaunaLife S4 is rated for six people, which realistically means four adults can stretch out without bumping knees. If you're planning backyard gatherings, the S4 gives you more room. For a more intimate setup, the Starlight is hard to beat.
Stove type: internal vs. external
Both of our models use stove configurations that keep the fire separate from the soaking area. If you want the fastest possible heat-up time, look for a submersible stove design. If you'd rather maximize interior space and don't mind waiting a bit longer, an external stove keeps things roomier inside. Either way, you'll want to stock up on seasoned hardwood. Oak, birch, or maple burn hotter and longer than softwoods like pine.
Off-grid or backyard?
Wood fired tubs are inherently off-grid. No electrical hookup, no dedicated circuit, no electrician visit. That makes them a strong choice for cabins, rural properties, or anywhere running power would be expensive or impractical. They work just as well in a suburban backyard. You'll just need a water source and a flat, level spot. If you're also considering an electric option for your home, our full hot tub collection covers both types.
Brands We Carry
Dundalk Leisurecraft — Handcrafted in Ontario, Canada from Eastern White Cedar. Dundalk has been building outdoor wood products for years, and their hot tubs use the same quality materials as their cedar sauna line. The Starlight comes with options for an aluminum or plastic interior liner, plus an optional roll-up cover for heat retention. Cedar naturally resists moisture and decay, so the exterior holds up well through seasons of outdoor use.
SaunaLife — Known for their barrel saunas and cube saunas, SaunaLife's S4 hot tub uses the same Scandinavian spruce they've built their sauna reputation on. It seats up to six, ships in two finish options, and pairs naturally with their outdoor sauna models if you're building out a full backyard setup. Shipping varies by configuration.
What's Included and What You'll Need
Both the Dundalk Starlight and SaunaLife S4 ship with the tub structure, stave or barrel components, and stove hardware. You'll need to provide firewood (seasoned hardwood works best), a garden hose for filling, and a flat, level surface. A compacted gravel pad or concrete slab both work well. No electrical work, no permits for the tub itself.
A roll-up cover is available as an add-on for the Dundalk Starlight and is worth considering if you're in a colder climate. Covers help retain heat during the firing process and keep debris out between soaks. Plan on draining and refilling the tub every few uses if you're not running a filtration system. Most owners find this takes about 15–30 minutes each way.
Water care without chemicals: Many wood fired hot tub owners skip the chlorine entirely. Drain after every 2–3 uses, wipe down the interior with a mild solution, and refill. If you'd rather keep water in longer, basic water treatment with bromine or a natural sanitizer extends the life of each fill to a few weeks. Saltwater is another option that's gentler on skin.
Pair your wood fired tub with an outdoor barrel sauna for a full backyard wellness setup, or add a cold plunge for contrast therapy. If you're interested in wood-burning sauna stoves, the same firewood that heats your tub works for your sauna. And if you need accessories like buckets, ladles, or covers, we carry those too.
