A wood-fired hot tub is a timber tub with a stove built into it. You fill it with water, light the stove and the fire heats the water directly, so the simplest versions need no electricity, no pump and no plumbing. It's the Nordic way to have a hot tub at the bottom of the garden, and running costs are just the wood you burn.
This guide covers how they work, the difference between Off grid, Premium and SPA versions, sizes, heating and wood, keeping the water clean, the base and the safety basics. The tubs we sell are made in Estonia by Palmako and delivered free to mainland Great Britain by lorry with a crane offload.
How a wood-fired hot tub works
The stove is built into the tub, so the fire heats the water directly through the stove's metal walls and the smoke leaves through a 2.7m chimney. As the water around the stove warms, it rises and cooler water moves in to replace it, so the tub circulates naturally while the fire is going. Stir the water now and then to even out the temperature.
Because there is no heater element, pump or control panel, an Off grid tub works anywhere you can fill it: the far end of the garden, a field or a holiday let. Our tubs are clad in thermowood, timber that has been heat-treated to make it more stable and resistant to rot, with a rich brown colour.
Off grid, Premium or SPA?
| Version | What you get | Electricity |
|---|---|---|
| Off grid | Tub with built-in wood-fired stove and chimney, steps and a thermal cover | None needed |
| Premium | As Off grid, plus LED lighting and a digital thermometer | Not needed for heating |
| SPA | As Premium, plus 12 air jets for a massage | Needs an outdoor supply for the jets, fitted by an electrician |
If you just want hot water and a view of the stars, Off grid is the purest and cheapest. The thermometer on Premium takes the guesswork out of heating. SPA is for people who want bubbles and are happy to run power to the tub.
Sizes and prices
| Tub | Size | Water | Seats | Off grid | Premium | SPA |
|---|---|---|---|---|---|---|
| Kilde round 2.0m | 2.01 x 2.01 x 0.95m | 1,150 litres | 6 | £3,750 | £3,990 | £4,250 |
| Kilde round 2.25m | 2.25 x 2.25 x 0.98m | 1,650 litres | 8 | £3,990 | £4,490 | £4,750 |
| Varme square | 2.03 x 2.03 x 0.96m | 1,500 litres | 6 | £3,990 | £4,250 | £4,490 |
Round tubs suit a lawn or gravel area and look traditional. A square tub fits neatly against a deck or into a corner and gives more legroom for the same footprint.
Heating it up and what to burn
How long a tub takes to heat depends on how cold the water is to start with, the weather, the size of the tub and how well you keep the fire going. From cold tap water, plan on a few hours, so light it well before you want to get in. These habits speed things up:
- Keep the thermal cover on while it heats. Most heat is lost from the surface.
- Burn dry wood. Wet wood smoulders, smokes and gives far less heat. Use logs with under 20% moisture: look for the Ready to Burn logo.
- Feed the fire little and often once it is going, rather than packing the stove.
- Stir the water every so often so the hot water at the top mixes with the cooler water below.
Most people bathe at around 37 to 40°C. Check the temperature before getting in (the Premium and SPA thermometer helps), and don't let it go above 40°C.
Keeping the water clean
An Off grid tub has no pump or filter, so the water is changed rather than filtered. How often depends on how much you use it and the weather: many owners refill after a weekend of use, or every few days in summer. Shower before getting in, keep the cover on between uses, and drain only once the stove and water have cooled.
If you want the water to last longer between changes, Palmako offers a sand filter as an optional extra for these tubs. Ask us about it when you order.
Base and placement
- A solid, level base. Filled and in use, these tubs weigh roughly 1.4 to 1.9 tonnes, so use a concrete slab or well-laid paving, not soft ground or an ordinary deck.
- Clear of buildings and trees. Keep the stove and its 2.7m chimney well away from buildings, fences, sheds and overhanging branches.
- Think about the smoke. Note which way the wind usually blows and where your neighbours sit outside. Dry wood makes far less smoke.
- Water and drainage. You need a hose to fill it and somewhere sensible for the water to go when you drain it.
- Access for delivery. The tub arrives on a lorry with a crane, so the lorry needs to get close enough to lift it to your drive or garden.
Most freestanding tubs don't need planning permission in England, but a raised deck over 0.3m, a listed building or designated land can change that. See Planning permission for garden saunas and hot tubs.
Safety
- Never light the stove unless the tub is full of water.
- The stove and chimney get very hot. Keep children and pets away from them, and supervise children in and around the water at all times.
- Don't bathe after drinking alcohol, and get out if you feel dizzy or too hot.
- Health conditions. If you are pregnant or have heart or blood pressure problems, ask your GP before using a hot tub.
- Cover it when not in use to keep heat in and children and animals out.
Hot tub, sauna and cold plunge
A wood-fired tub pairs well with a garden sauna and a cold plunge: sauna, a quick cold dip, then a long soak in warm water. See our garden sauna buying guide and cold plunge guide.
Common questions
Does a wood-fired hot tub need electricity?
Not the Off grid version: the built-in stove heats the water. The SPA version needs an electricity supply for its 12 air jets.
How long does a wood-fired hot tub take to heat?
A few hours from cold water, depending on the starting temperature, the weather, the size of the tub and how well the fire is kept going. Keep the cover on and burn dry wood to speed it up.
How many people fit in a wood-fired hot tub?
Our Kilde 2.0m and Varme seat 6, and the Kilde 2.25m seats 8.
How often do you change the water?
An Off grid tub has no filter, so the water is changed regularly, often after a weekend of use or every few days in warm weather. An optional sand filter helps the water last longer.
Do I need planning permission for a hot tub?
Usually not for a freestanding tub in a back garden in England. Raised decking over 0.3m, listed buildings and designated land such as conservation areas have stricter rules.
When can I have one?
Our tubs are new for Palmako's 2027 range and made to order. We confirm the delivery date with you when you order.
Choose your hot tub
Round or square, Off grid, Premium or SPA, delivered free to mainland Great Britain with a crane offload.
