Gas Sauna Heater — Botnia 81, 8.1 kW Off-Grid Propane | FinSteam
Finsteam · our rating 51
Independent comparison: we may earn a commission when you buy through links on this page. It never affects how we rank products — see our method.
Options (4)
Where to buy
| Retailer | Price | RRP | 30-day change | |
|---|---|---|---|---|
| Steam & Oak | £1,695 | — | — | View at Steam & Oak |
Price history
Price tracking started 2026-07-17 — the history chart appears once we have a few days of data.
Specs
| Features | canopy |
|---|
Steam & Oak is the first UK retail partner for FinSteam — bringing this Finnish gas sauna engineering to British gardens, off-grid cabins, custom builds and existing-sauna retrofits. The original FinSteam gas heater — drop into your existing sauna, or build around it The Botnia 81 is the original FinSteam workhorse — 8.1 kW, certified, the heater that started the brand. Drop it into your existing barrel sauna, cube sauna, cabin, custom build, or off-grid setup; or buy it to specify a new sauna around. Connect a UK propane bottle outside via a 37 mbar regulator, light the heater, and you're in genuine 70-75°C Finnish sauna heat in 15 to 20 minutes. No electricity, no chimney, no flue. Turn the dial. Upgrading your current sauna? Here's what fits where The Botnia 81 is certified as a standalone gas appliance, which means it can be installed in any sauna structure provided you meet the FinSteam installation specifications (clearances, ventilation, base, gas connection). Common retrofit scenarios: Existing barrel sauna with no heater fitted (very common with imported Eastern European barrels) — the Botnia 81 R11S or R14S is the typical pick. The Njord heat shield in the S variants cuts the required side clearance right down to 50 mm — handy for the tightest barrels and curved walls, and for extra safety margin on any fixed install. Existing barrel / cabin with a tired wood-fired stove — replace it with a Botnia and you skip the chimney, the fire-tending, the 30-45 minute warm-up. Same sauna, a much better daily experience. Existing electric sauna with a dead element — replace the element + heater + the consumer-unit + the electrician callout with a Botnia. No more sauna-trips-the-fuses, no more circuit upgrades. Custom build / self-build — buy the Botnia 81 O (base, no cage) if you're sourcing your own Orbis cage, or any of the R configurations to ship matched and ready. Off-grid cabin / cottage / Airbnb — the Botnia is the easiest way to add real sauna heat where the mains can't reach. Why a gas sauna heater (and why it beats wood-fired or electric) For owners considering an upgrade, the headline comparison: FinSteam gas Wood-fired Electric Heat-up time ~15 minutes, turn a dial 30-45 minutes, tend a fire 30-60 minutes Power needed Propane bottle Firewood Mains — often a dedicated 32A circuit Electrician / wiring None None Usually required (£1-2k) Chimney None Required None Smoke, ash, soot None Yes, every session None Humidity Naturally humid (combustion vapour stays in the cabin) Dry until you ladle Dry until you ladle Off-grid Yes Yes No Control Dial The fire decides Thermostat / timer Safety EU-certified, auto oxygen shut-off Open flame Electrical Works in a power cut Yes Yes No A clever piece of engineering — the certified safety case Running gas safely inside a small, enclosed, oxygen-hungry space like a sauna is genuinely hard. FinSteam solved it with patented burner technology delivering clean, stable combustion, wrapped in two layers of automatic safety: Oxygen Depletion Sensor (ODS) — continuously monitors the oxygen level inside the sauna and automatically shuts off the gas if it drops to approximately 18% — well above any level dangerous to occupants. This is the same standard used in indoor gas appliances regulated by the EU. Flame monitoring — cuts the gas instantly if the flame is lost for any reason (e.g. accidental knock, sudden draft, gas supply interruption). FinSteam's stated claim: this is the only CE-marked, electricity-free sauna gas heater on the European market. AENOR-tested under EU Gas Appliance Regulation 2016/426. Across the last 12 months, FinSteam record zero warranty returns on the heater. Will it fit my sauna? Insulated saunas: 4 to 12 m³ internal volume — covers virtually every domestic barrel, cube, cabin and custom build. Non-insulated saunas / tents / lightweight builds: 4 to 8 m³ — the lower insulation means less working volume. Heating speed: 15 to 20 minutes from cold to 70-75°C in normal UK
