Wood-burning or electric
The sauna heater decides how quickly the room warms, how the steam feels and what your weekly routine looks like. This guide explains wood-burning and electric heaters, how to match output to the room and what the installation needs.
From our customers
Customer projects matched to the products listed on this page. Earlier specifications and selected options may differ.
Customer projects from United Kingdom.
Hello Albertas, I promised to send some pictures of the sauna, see attached. We were so impressed with every aspect of working with your company, I wish all the suppliers we have dealt with were this good. very best Davi…
Hello Albertas, I promised to send some pictures of the sauna, see attached. We were so impressed with every aspect of working with your company, I wish all the suppliers we have dealt with were this good. very best David
Hello, Absolutely stunning. Build quality is excellent: sturdy and lovely finish inside and out. The insulation is impressively effective- which filters out sound as well as keeping in the heat. All in all, this has exce…
Hello, Absolutely stunning. Build quality is excellent: sturdy and lovely finish inside and out. The insulation is impressively effective- which filters out sound as well as keeping in the heat. All in all, this has exceeded all of my expectations, absolutely love it!
Review and installation photos →Hi Albertas, The spa is in its final location - but won’t be installed for another month! There is more work to do on the landscaping… But everything looks great so far! Kevin
Each of these models is supplied with one Harvia heater. On the product page you pick a wood-burning stove with chimney or an electric heater, and the heater list only shows the sizes suited to that sauna room. The card price is the model’s current starting price.
A wood-burning sauna heater is a firebox with a stone basket above or around it and a flue that leaves through the roof. You light it, feed it logs and manage the fire. Many people choose it for the soft, rolling heat, the sound and the fact that it needs no large electrical supply. It suits gardens away from the house, holiday cabins and owners who enjoy the ritual.
An electric sauna heater warms a stone mass with elements. You switch it on, set a temperature and, with a Wi-Fi controller, you can start it from the house. It is cleaner, quieter and easier for short weekday sessions, but it needs a dedicated supply installed and certified by a qualified electrician.
| Question | Wood-burning stove | Electric heater |
|---|---|---|
| Daily routine | Light, feed and watch the fire; clear ash | Switch on or schedule; very little cleaning |
| Services needed | Chimney, safe clearances, dry log storage | Dedicated electrical supply and isolation |
| Feel of the heat | Strong, lively steam from a large stone load | Even, controllable heat; steam depends on stone volume |
| Best suited to | Off-grid sites, rural gardens, those who like the ritual | Frequent short sessions, urban gardens, smoke-sensitive neighbours |
Heater output is matched to the volume of the hot room, not to the outside length of the sauna. A porch or changing room does not count, because it is not heated. Glass walls and uninsulated timber lose more heat, so a glazed front or a cold, exposed site may justify the next size up.
The UK product options follow the manufacturer’s guidance by length of the sauna room:
An undersized heater runs flat out and still struggles in winter; an oversized one can make the upper bench harsh before the stones are fully hot. If your planned use sits between two sizes, ask us to check the room and glazing before you order.
The chimney supplied with the stove must run through the roof with the correct clearances and roof flashing. Keep the guard in place, leave the specified distance to timber and benches, and store logs dry and close to the door. Seasoned hardwood with low moisture burns cleaner and gives more heat. An outside-loading (SL) stove keeps ash and log handling out of the hot room, which many owners prefer.
The Cilindro PC90 and PC90XW run on 400 V three-phase (3 × 16 A); the PC90 can also run on 230 V single-phase with a larger supply cable, and the Legend PO110FC is 400 V three-phase. Most UK homes have a single-phase supply, so confirm the heater against your consumer unit early. A qualified electrician designs and certifies the circuit, isolator and cable route.
Safety first: follow the heater’s installation manual, never cover or dry clothes on a heater, and keep children supervised. Anyone with a medical condition should take advice before using a sauna.
Sauna stones store the heat and turn ladled water into steam. Load them loosely so air can move, and re-stack them each season, replacing any that crack or crumble. Use clean water on the stones; scented additives belong in a bucket, not poured neat. After a session, leave the door or vent open so the room dries, and on a wood-burning stove clear the ash once it is cold.
Want to plan the whole room? The outdoor sauna range explains shapes and sizes, and the wood fired sauna page covers chimneys and stove-ready models in more depth. For an electric build, see electric outdoor saunas.
Neither is better in every garden. Wood suits a hands-on routine and sites without a large electrical supply; electric suits short, frequent sessions and remote starting. Choose the one you will happily use in midwinter.
Match the heater to the heated room only. On our saunas the M3 suits rooms of about 2–4 m and the 20 PRO about 4–5 m; the Cilindro PC90 suits about 2–3 m. Glazing or an exposed site can justify a larger size.
The Cilindro PC90 can be wired for 230 V single-phase with a heavier supply; the other electric options listed are 400 V three-phase. Your electrician confirms what your property can support.
Each sauna above includes one Harvia heater: the M3 wood-burning stove with chimney or the Cilindro PC90 electric heater. The other heaters are upgrades selected on the product page.
Tell us the model, how often you will use it and what supply you have, and we will suggest a heater and explain the installation.
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