Sauna Accessories Worth Buying

Needed for an electric sauna

Heater stones

Most heaters ship without stones. Use the stone size given in the manual; olivine diabase and peridotite are the usual Finnish heater stones. Re-stack or replace them when they crumble, typically every year or two with regular use.

Example: Harvia 20 kg stones →

Control unit

Check

Some heaters, such as Harvia models ending in E, need a separate control panel. Check the product page before ordering so the heater is not delivered without one.

Bucket and ladle

The Finnish kiulu and kauha. Choose wood or metal with a long ladle handle so your hand stays out of the steam. Avoid plastic near the heater.

Needed for a wood-burning sauna

Chimney and flue kit

Certified for sauna stoves and installed with the clearances in the stove manual.

Non-combustible floor plate

Under and in front of the stove when the floor is combustible. The stove manual gives the size.

Smoke and carbon monoxide alarm

In the dressing room or adjoining space, not in the hot room.

Wood stoves also need stones and a bucket and ladle, listed above.

Worth having

Thermometer and hygrometer

Mount it at head height on the bench side, away from the heater, so it shows what you actually feel.

Wireless sauna sensor

Shows temperature and humidity on your phone, so you know when the sauna is ready. The Finnish RuuviTag is a popular choice; for the hot room, look for a version with an external probe.

Ruuvi sensors →

Heat-rated lighting

Ordinary LEDs fail at sauna temperatures. Use fittings sold for saunas and place them low, behind the backrest or under the benches.

Adjustable vents

Fresh air in above or beside the heater, exhaust low under the benches. Adjustable valves let you close them during warm-up.

Ventilation calculator →

Heater safety railing

Heater makers sell railings for specific models. Worth it if children or guests use the sauna.

How many sauna stones do you need?

Stones usually come in 20 kg (44 lb) bags. The amount depends on the heater model, not the room.

Heater	Type	Stones	Stones (lb)	20 kg bags
Harvia Vega BC45	Electric	20 kg	44 lb	1
Harvia Vega BC60	Electric	20 kg	44 lb	1
Harvia Vega BC80	Electric	20 kg	44 lb	1
Harvia Vega BC90E	Electric	20 kg	44 lb	1
Harvia Cilindro PC70XW	Electric	90 kg	198 lb	5
Harvia KIP60	Electric	20 kg	44 lb	1
Harvia KIP80	Electric	25 kg	55 lb	2
Helo Himalaya 70	Electric	100 kg	220 lb	5
Finlandia FLB-80S	Electric	23 kg	51 lb	2
Amerec Laava-10.5	Electric	60 kg	132 lb	3
Tulikivi Usva M 45	Electric	30 kg	66 lb	2
Tulikivi Usva M 68	Electric	30 kg	66 lb	2
Tulikivi Usva M 85	Electric	30 kg	66 lb	2
Tulikivi Usva M 102	Electric	30 kg	66 lb	2
Harvia M3	Wood	30 kg	66 lb	2
Harvia Legend 150	Wood	120 kg	265 lb	6
Harvia Pro 20	Wood	40 kg	88 lb	2
HUUM Hive Wood 13	Wood	90 kg	198 lb	5
HUUM Hive Wood 17	Wood	130 kg	287 lb	7
Kastor Karhu 20	Wood	32 kg	71 lb	2
IKI Original	Wood	300 kg	661 lb	15
Narvi Aito AK-47	Wood	60 kg	132 lb	3
Narvi Aito AK-57	Wood	90 kg	198 lb	5
Narvi Aito AK-57K	Wood	130 kg	287 lb	7
Narvi Aito 68	Wood	200 kg	441 lb	10
Narvi Aito 78	Wood	240 kg	529 lb	12

For other models, the installation manual gives the amount and stone size. The calculator shows it when you pick a heater.

What to skip

Varnish or lacquer for the benches. Leave bench wood bare, or use paraffin oil or a sauna wax. Varnish gets sticky and hot.
Garden or decorative stones on the heater. Stones not made for heaters can crack in the heat. Use stones sold for sauna heaters.
Household light fittings and electronics. Anything in the hot room must be rated for sauna temperatures.
Plastic buckets next to the heater. They soften and can deform close to the stones.
Fragrances poured straight on the stones. If you use them, choose ones made for saunas, dilute them in the ladle water and follow the heater manual.