Electric Sauna Running Costs vs Gas: The Honest 2026 Numbers

The honest truth: electric and gas saunas cost roughly the same to run, at 2026 UK energy prices. A typical session costs £2–£3 on either fuel. The real difference isn't energy bills—it's what you avoid. Gas removes the electrician (£800–£1,500 install), the three-phase problems (£3,000+ upgrades), and the heating element failures (£250+ repairs). You choose gas for simplicity and reliability, not to cut your energy bill. For anyone claiming gas is "cheaper to run," they're selling you an energy story that doesn't hold up. Here's the honest breakdown with current rates.

Electric sauna running cost per session

A typical electric sauna heater draws 6–8 kW. One session at 70°C ("sauna-ready in under 20 minutes, typical") and maintained for 45 minutes uses roughly 4.5–6 kWh of electricity.

At the current UK price cap (July 2026), domestic electricity is approximately 28p/kWh (this fluctuates quarterly; check your supplier for exact rates). A 5.5 kWh session costs:

5.5 kWh × £0.28/kWh = £1.54 per session

This assumes a 70% average efficiency (not peak output, because the heater ramps to temperature and then maintains, not running at full 8 kW for the entire 45 minutes). A longer session (60+ minutes) uses 6–7 kWh, costing £1.68–£1.96 per session.

Add 5% standing charge allocation per session (roughly £0.10), and a realistic electric cost per session is £1.60–£2.10 for casual use, £2.20–£2.80 for heavier use (3+ sessions per week, longer sessions).

Gas sauna running cost per session

A FinSteam Botnia or Aurora heater (8.1 kW) burns propane at approximately 0.6 kg/hour at full power. A 45-minute session at full power uses 0.45 kg of propane.

Current UK propane prices (July 2026) for domestic bottles: approximately £2.80–£3.50 per kg. This varies by supplier and bottle size; a 13 kg economy bottle averages £2.50/kg, while a 6 kg portable bottle averages £3.20/kg.

At £3.00/kg (mid-range):

0.45 kg × £3.00/kg = £1.35 per session

However, real sessions vary. Many users run at 50–70% power after initial heat-up, reducing consumption to 0.25–0.35 kg per session. A realistic figure is about £2–£3 per session — nearer £3 on a 6 kg portable bottle, £2–£2.50 on an economy 13 kg bottle.

Accounting for delivery (some suppliers charge per bottle delivery; others bundle it), the practical range is £1.50–£3.00 per session on propane.

Cost comparison table

Why the running costs are so similar

Both fuels convert to thermal energy efficiently. An electric heater converts electricity to heat at ~90% efficiency. A gas heater combusts propane to heat at ~85% efficiency (combustion losses, but no chimney, so all losses stay inside the sauna).

The energy content is different: electricity costs more per unit energy than propane in the UK (roughly 28p/kWh vs ~£3.00 per kg of propane, which contains ~12.5 kWh). But electric heaters are smaller (6–8 kW domestic) while gas heaters often run at partial power after initial heat-up.

The net result: £1.60–£2.80 per session either way, depending on usage pattern. The variation is greater between individual users (how long you heat, how much you sweat) than between the fuels themselves.

What about the price cap fluctuation?

UK electricity prices are volatile. Since 2021, the price cap has swung from 25p/kWh to 55p/kWh. If you're an electric sauna user and the price cap rises to 50p/kWh (as it did in early 2023), your session cost jumps to £2.75–£3.50.

Propane prices also fluctuate, but they're typically more stable than grid electricity. More importantly, propane is a physical commodity you buy in bottles, not a quarterly price cap adjustment. You know your cost upfront.

For budget planners, gas offers price predictability; electric offers grid-scale price volatility.

The cost of installation is the real difference

Running an electric sauna costs £1.60–£2.80 per session. Installing one costs £800–£1,500 in electrician and compliance, plus potentially £3,000–£7,000 for three-phase upgrade or consumer unit upgrades.

Running a gas sauna costs £1.35–£2.50 per session. Installing one costs £0 (portable, no electrician, no three-phase needed).

Over 10 years of weekly sauna use (500 sessions):

• Electric: £800–£1,500 (install) + £800–£1,400 (500 sessions at ~£1.60–£2.80) + £250–£400 (element replacement) = £1,850–£3,300
• Gas: £0 (portable install) + £675–£1,250 (500 sessions at ~£1.35–£2.50) + £89 (regulator kit, one-time) = £764–£1,339

The saving is £1,000–£2,000 on the installation side, not on energy bills. Gas wins because you avoid the electrician, the wiring, the compliance overhead, and the element failures—not because gas is a cheaper fuel.

Who should choose electric?

Electric saunas suit:

• Urban flats where venting combustion products is problematic
• Buyers who philosophically prefer electricity over fossil fuels
• Facilities with three-phase already installed (commercial gyms, wellness centres)

For everyone else—especially rural, off-grid, or garden sauna users—gas removes so much installation friction that the small (or zero) energy bill saving is secondary.

The honest framing

You don't choose gas to cut your energy bill. You choose gas because you avoid the electrician, the three-phase problem, the heating element failure, and the Building Regulations paperwork. Running costs are roughly level; the advantage is simplicity and reliability over 10 years.

Sources

UK electricity price cap (Ofgem, July 2026); domestic propane pricing (BOC, Calor, Flogas current rates, July 2026); electric heater efficiency (Harvia technical data, 2025); FinSteam propane consumption rate (Botnia/Aurora technical specifications, 8.1 kW at 0.6 kg/h); price volatility analysis (Ofgem historical price cap data, 2021–2026).