A wood fired hot tub usually takes 2–4 hours to heat from cold to 38°C in Ireland. The wood fired hot tub heat time depends on the stove type, the water volume, the weather and how dry your logs are.
Wood fired hot tub heat times
| Set-up | From cold (8–10°C) | Logs used |
|---|---|---|
| Internal stove, 1,000 L | 2–3 hours | 10–15 kg |
| External stove, 1,000 L | 2.5–3.5 hours | 12–18 kg |
| Large tub, 1,500 L+ | 3–4+ hours | 15–25 kg |
What speeds it up
- Dry hardwood: logs under 20% moisture burn hotter. Wet wood can double the heat time.
- A lid: keep the cover on while heating to cut heat loss.
- Warmer fill water: topping up with some warm water from the house shortens the wait.
- Stir the water: hot water rises, so stir every 30 minutes to spread the heat.
- Shelter: a spot out of the wind makes a big difference in an Irish winter.
Internal or external stove?
An internal stove sits in the water, so it heats faster but takes up seating space. An external stove sits outside the tub, so the water is free of hot metal, which is safer with children. For more on the trade-offs, see wood-fired vs electric hot tubs.
Keeping it hot
Once it is at 38–40°C, a log every 20–30 minutes keeps it there. With a good insulated lid, the water will still be warm the next morning. For log-burning advice, SEAI has guidance on burning dry wood efficiently.
Frequently asked questions
How long does a wood fired hot tub take to heat?
Usually 2–4 hours from cold, depending on the stove, water volume, weather and logs.
How much wood does a wood fired hot tub use?
Roughly 10–25 kg of logs to heat from cold, then a log every 20–30 minutes to keep it hot.
Can I heat a wood fired hot tub faster?
Yes. Use dry hardwood, keep the lid on, stir the water and start with some warm water if you can.
Can you leave a wood fired hot tub full?
Yes, for a few days with a cover. For longer, use a sanitiser or drain it, especially in summer.
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Internal and external stove models delivered across Ireland.
