Wood-Fired vs Gas vs Electric Saunas: Which Heater Is Right for You?
The heater is the single most important decision in an outdoor sauna. It sets how long you wait for heat, what it costs to run, whether you need an electrician, and how the heat actually feels. There are three ways to power a sauna — wood-fired, electric and gas — and each is genuinely the right answer for someone. Here's an honest comparison, including where each one loses people. (We sell all three, which is exactly why you can trust this.)
The quick answer: which sauna heater is for you?
- Electric — if you already have a spare circuit and want set-and-forget timer control.
- Wood-fired — if the ritual of the fire is part of the experience, and you're not in a smoke-control area.
- Gas (flueless) — if you want no electrician, off-grid placement and the fastest heat-up.
How do saunas work? Direct vs indirect heat
Every sauna heater warms the room in one of two ways, and it explains almost everything about how each performs.
Electric and wood-fired heaters heat indirectly. They first heat a large thermal mass — the stones and the metal body — and that mass then slowly warms the air. It's effective but slow, because the energy is stored in the stones before it reaches you.
A flueless gas heater heats directly. It burns gas and delivers the hot air and water vapour it produces straight into the room, while also heating the stones for löyly. Because it doesn't have to charge up a thermal mass first — and loses nothing up a chimney — it's ready far faster. (For the full science, see How a gas sauna heater works.)
Wood-fired saunas
For many people, the wood-fired sauna is the real thing: the crackle of the fire, the smell of woodsmoke, the slow ritual of building the heat. It's completely off-grid — no electricity needed — and there's an authenticity to it that neither electric nor gas quite matches.
The trade-offs are logistics. You'll spend 30–45 minutes building and tending the fire before anyone gets warm; there's a chimney to install and sweep, logs to buy, split, season and store, ash to clear, and smoke drifting over the fence. And critically, most large UK towns and cities are smoke-control areas, which restrict what you can burn — making a wood-burner a genuine compliance question anywhere urban.
Best for: rural properties with space and no smoke restrictions, and people for whom tending the fire is the point.
Electric saunas
Electric is the default for a reason: precise thermostat and timer control (set it and forget it), low maintenance, no chimney, no fuel to store, and the widest choice of heaters on the market. For an indoor sauna, or an outdoor one where the electrics are already sorted, it's hard to beat.
The catch is at the consumer unit. A 7–9 kW electric heater can't run off a normal socket — it needs its own dedicated circuit installed and signed off by a qualified electrician under Part P, typically £800–£1,500 on top of the sauna, plus the wait to get one booked. It's also tied to one building and can't go off-grid, and the heat is dry until you throw water.
Best for: indoor saunas, and anyone who already has (or is happy to pay for) the dedicated circuit.
Gas (flueless) saunas
A flueless gas sauna is the newest option in the UK and, for the right buyer, the most convenient. Because it heats directly and runs on a standard propane bottle, it's ready in about 15 minutes, needs no electrician and no mains power, and has no chimney — so no smoke, and no problem in smoke-control areas. Combustion produces water vapour, so the cabin has a soft natural humidity from the moment it lights, with full löyly off the stones. FinSteam describe theirs as the only CE-marked, electricity-free gas sauna heater on the European market.
The trade-offs: there's a propane bottle to swap every couple of months, ventilation is mandatory (two passive vents, done properly), and it's LPG — a fossil fuel, so it won't be the lowest-carbon option if you have renewable electricity.
Best for: no-electrician builds, off-grid and remote spots, mobile and commercial sauna operators, and urban gardens where wood-burning isn't allowed.
Wood-fired vs gas vs electric: the comparison table
| Wood-fired | Electric | Gas (FinSteam, flueless) | |
|---|---|---|---|
| How it heats | Indirectly, via the stones | Indirectly, via the stones | Directly — hot air into the room |
| Ready from cold | 30–45 min, tending a fire | 30–45 min | ~15 minutes, on a dial |
| Power needed | Firewood | Dedicated mains circuit | Propane bottle |
| Electrician / wiring | None | Required (Part P, £800–£1,500) | None |
| Chimney | Required | None | None |
| Smoke & ash | Yes, plus clean-up | None | None |
| Humidity | Dry until löyly | Dry until löyly | Natural, from the moment it lights |
| Off-grid | Yes | No | Yes |
| Smoke-control areas | Restricted | No restrictions | No restrictions |
| Control | The fire decides | Thermostat / timer | Adjustable dial |
| Running cost / session | ~£2–£2.50 | ~£1.50–£2 | ~£1.80 |
Sauna running costs: is gas cheaper than electric?
Honestly, not by much. All three fuels land in the same band — roughly £1.50–£2.50 a session at current UK prices. Gas comes in around £1.80, about level with electric and a little cheaper than wood. So don't choose a fuel to save on running costs; the difference is small. Choose it for placement and convenience: whether you need an electrician, whether it can go off-grid, and how long you're willing to wait for heat.
Off-grid saunas: why gas (or wood) wins without mains power
If your ideal sauna spot has no power — the bottom of a long garden, a paddock, a glamping field, a beach for the swim club — electric is out before you start. Wood-fired works off-grid but brings the smoke and the logistics. A flueless gas sauna is the low-effort off-grid answer: stand the cabin, stand a propane bottle beside it, and you're minutes from heat, in summer or a British winter. It's why gas has become the go-to for mobile sauna hire and off-grid builds.
So which should you choose?
- No spare circuit, or no appetite for an electrician? Gas.
- The fire is the ritual for you? Wood-fired.
- Indoors, or already have the circuit, and want set-and-forget? Electric.
- Off-grid, mobile or commercial? Gas.
- Urban garden in a smoke-control area? Gas or electric.
Frequently asked questions
Is a wood-fired sauna better than electric?
Neither is universally better — it's about fit. Wood-fired gives an authentic, off-grid, fire-tended experience but needs a chimney and 30–45 minutes of fire-tending, and is restricted in smoke-control areas. Electric is faster to control and lower-maintenance but needs a dedicated circuit and an electrician, and can't go off-grid.
How do saunas work?
A sauna heater warms a bed of stones, which heat the air to around 70–100 °C; throwing water on the hot stones produces löyly (steam). Electric and wood heat the stones indirectly and take 30–45 minutes; a flueless gas heater also heats the air directly, so it reaches temperature in about 15 minutes.
Is gas or electric cheaper to run a sauna?
They're roughly level — about £1.50–£2 a session for electric and ~£1.80 for gas at current UK prices. The saving isn't the reason to choose one over the other; installation and placement are.
Can you use a sauna off-grid?
Yes — with a wood-fired or a flueless gas sauna, both of which run without mains power. A flueless gas sauna is the lower-effort option: no chimney, no fire-tending, ready in about 15 minutes off a propane bottle.
Do gas saunas heat up faster than electric or wood?
A flueless gas sauna does — about 15 minutes from cold, versus 30–45 minutes for electric or wood — because it heats the air directly rather than storing heat in the stones first.
Do I need an electrician for a sauna?
For an electric sauna, yes — a 7–9 kW heater needs a dedicated circuit installed and signed off under Part P. Wood-fired and gas saunas need no electrician.
New to saunas? It helps to know the difference between a steam room and a sauna first.
Explore your options. Browse wood-fired, gas and outdoor saunas, compare the Botnia 81 and Aurora 81 gas heaters, or start with a ready-built gas package: Ember Base (£2,495) · Ember Complete (£2,695) · NOIR L (£3,995). New to saunas? Read the steam room vs sauna guide first. Tell us your spot and we'll recommend the right heater — including electric or wood if that's the honest answer.
