Sauna Heater with Rocks

Sauna heaters with rocks: electric or wood-burning

A sauna heater with rocks, sometimes called a sauna rock heater or a stone sauna heater, heats a load of sauna stones. The manual for every electric heater here describes throwing or ladling water onto the hot stones: Harvia's say the water raises the humidity, HUUM's DROP and HIVE manuals ask for clean, warm water once the stones are fully heated, and Saunum's manuals ask for hot water from a sauna ladle.

The stones in a sauna heater with rocks are heated either by electricity or by a wood fire. For the wood stoves here, Harvia's manuals name dry wood as the best fuel and HUUM's allow wood only.

Which heat source suits a sauna is weighed in wood vs electric sauna heaters compared; the facts that decide it here are these:

• Choose electric if the sauna can have a 240 V supply. Every electric heater here, from all three makers, runs on 240 V.
• Choose a wood stove such as Harvia's M3 or HUUM's HIVE Wood if the sauna has no electrical supply. Topture's listing of the M3 gives the stove no electrical connection, and HUUM describes its HIVE Wood as a choice for saunas without access to electrical connections. Every wood stove here is sold with a chimney kit; for its own stoves, HUUM's manuals leave the chimney connection to a specialist or a certified installation expert.
• Choose an LS model to load the fire from outside the sauna room: HUUM's HIVE Wood 17 LS, HIVE Flow LS and HIVE Flow Mini LS are installed through a non-combustible wall, so the fire is loaded from the next room; the other eight wood stoves here are loaded from inside the sauna room. Compare them with the other outside-feed wood sauna stoves.
• Rule out this collection if you want a whole sauna room. The products here are heaters; complete saunas are under traditional saunas.

Sauna heaters with rocks compared by room size

A sauna heater with rocks is sized to the volume of the sauna room: Harvia and HUUM print a minimum and a maximum room volume for each of their heaters here, and the heater to choose is one whose range covers your room. Saunum's Air manuals size the same way and say to choose the larger heater when a room falls between two sizes. To find the room's volume, multiply its length, width and height in feet, which gives cubic feet.

Before comparing, add the maker's allowance for walls without insulation. Harvia adds about 3.9 cubic feet for each square foot of uninsulated brick, glass block, glass, concrete or tile wall, glass doors included, and multiplies a solid-log room by 1.5. HUUM's manuals for its floor-standing electric heaters and for the HIVE Flow add 3.3 cubic feet for each square foot of uninsulated brick, tile or glass wall. Saunum adds 3.0 cubic feet per square foot of glass, tile, brick, concrete or stone, and multiplies the room's volume by 1.5 when its log, plank or stave walls have no inside insulation.

• For a room of 106 to 177 cubic feet: start with Harvia's KIP 4.5 kW (100–210 cubic feet), HUUM's DROP 4.5 kW (106–248) or HUUM's CLIFF Mini and STEEL Mini (106–177 each).
• For a room of 177 to 300 cubic feet: start with Harvia's KIP 6 kW (170–300) or one of HUUM's 6 kW heaters, the DROP, CLIFF, STEEL and HIVE Mini (177–318 each); for wood heat above 212 cubic feet, Harvia's M3 and HUUM's HIVE Wood 13 both cover 212 to 459.
• For a room of 300 to 460 cubic feet: start with one of HUUM's 9 kW heaters, the DROP, CLIFF, STEEL and HIVE Mini (283–460 each), Harvia's Virta 9 kW (177–494) or, up to 425 cubic feet, its KIP 8 kW (250–425); for wood heat, HUUM's HIVE Flow covers 282 to 635 and its HIVE Wood 17 covers 283 to 565.
• For a room of 460 to 636 cubic feet: start with HUUM's HIVE 12 kW (424–636), Harvia's Virta 10.5 kW (177–635), Cilindro Half 10.5 kW (141–636) or, up to 600 cubic feet, Club 10 kW (390–600); for wood heat, Harvia's Pro 20 covers 283 to 706.
• For a room above 636 cubic feet: start with HUUM's HIVE 15 kW (530–813) or HIVE 18 kW (636–989), or Harvia's Club 12.5 kW (500–750).
• Rule out a heater whose printed range does not include your room's volume once the allowances are added, however its other figures compare.

Stone load in sauna heaters with rocks

The stone load of a sauna heater with rocks is set by its maker, and two heaters of the same output can carry very different loads: HUUM's manuals give the DROP 6 kW about 121.3 lb of stones and the STEEL 6 kW about 330 lb.

• If you want a heater that hangs on the wall: start with Harvia's KIP, which holds 44 lb of stones, or HUUM's DROP.
• For a large stone load: choose a floor-standing heater such as HUUM's STEEL, its HIVE Mini at 331 lb or its HIVE at 551 lb (250 kg), or Harvia's Cilindro Half 10.5 kW, which takes up to 265 lb.
• For a wood stove with a large load: choose HUUM's HIVE Flow, which takes 330 lb (150 kg) of stones, or the HIVE Flow Mini with 231 lb; Harvia's M3 and Pro 20 take 66.2 lb and 88.2 lb.
• If you would rather not buy stones separately, pick a HUUM or Saunum heater here, a Harvia KIP, Virta, Virta Combi or Cilindro Half package, or a wood stove: each lists the heater's stones among its contents.

Controls and Wi-Fi on sauna heaters with rocks

A sauna heater with rocks that runs on electricity is set and switched from a control, on the heater or on a separate panel. Harvia's KIP packages with built-in controls put the thermostat and timer on the heater itself, and every other electric heater here runs from a separate control.

The temperature these controls can be set to differs by maker: HUUM's UKU can be set up to 230°F (110°C), or 194°F (90°C) with its bench sensor fitted, and Harvia's Xenio controls have a setting range of 104–194°F (40–90°C).

• Controls on the heater and no app: choose one of Harvia's four KIP packages with built-in controls; Harvia documents no Wi-Fi control for them.
• App control from a phone: pick a package whose control connects to an app. The Xenio Wi-Fi controls in Harvia's KIP packages with digital controls and in its Virta, Virta Combi and Cilindro Half packages work with the MyHarvia app, Saunum's Air IQ with the Saunum app, and HUUM's UKU Wi-Fi with HUUM's app when you choose it over the UKU Local; compare them with other sauna heaters with Wi-Fi control.
• A wall panel without an app: choose HUUM's UKU Local, which is run from its wall panel only, with no app.

Electrical supply for sauna heaters with rocks

A sauna heater with rocks that runs on electricity needs its supply planned before it is ordered. HUUM's UKU manual asks for the control's own dedicated circuit and says the electrical work it describes may only be done by a licensed electrician.

• For a 208 V three-phase supply: choose one of the two Harvia packages here listed for it as well as for 240 V, the multi-size KIP package with Xenio Wi-Fi control and the Club 10 kW.
• Compare the amps before choosing between sizes: HUUM's manuals list the DROP 4.5 kW at 18.75 amps on 240 V and the HIVE 18 kW at 75 amps, and Harvia's KIP manual lists the KIP 4.5 kW at 18.8 amps, so take the maker's figure to your electrician first.

Your licensed electrician sizes the breaker and wire from the manual that ships with the heater and your local code.

How much does a sauna heater with rocks cost?

Prices of the sauna heaters with rocks here start at $1,214 for Harvia's KIP 4.5 kW package with built-in controls, and Harvia's KIP packages fill the lower end of the range; HUUM's electric HIVE 12, 15 and 18 kW packages sit at the upper end, the HIVE 18 kW from $6,471.

What the price covers, and what it leaves out:

• HUUM HIVE 12, 15 and 18 kW: the package adds HUUM's UKU Extension Box, because HUUM's UKU runs heaters up to 11 kW on its own.
• Harvia wood kits: the two M3 kits with a sheath and the Pro 20 kit add Harvia's protective sheath and bedding.
• If you choose a wood stove, budget for what its package leaves out: HUUM's HIVE Flow and HIVE Flow Mini packages leave out the sheet-metal floor plate HUUM requires in front of the door on a combustible floor, and their LS versions leave out the floor plate in front of the door and the mounting collar; HUUM's HIVE Wood packages leave out extension pipes, and the HIVE Wood 17 LS package also has no floor bed and leaves out the floor protection in front of the firebox door; and Harvia's M3 kit with chimney and stones leaves out the protective bedding for a tile or combustible floor.
• If you already own a control or stones, buy the heater alone from electric sauna heaters or wood-burning sauna heaters.

Topture is an authorized Harvia retailer, an authorized HUUM retailer listed as an E-shop in HUUM's dealer directory, and an authorized Saunum retailer, and each heater here carries its maker's warranty on that maker's terms: see the Harvia sauna heaters, HUUM sauna heaters and Saunum sauna heaters pages. Shipping to the contiguous United States is included on every heater in this collection, with an electric heater usually sent by UPS or FedEx and a wood stove by freight; the rest of buying a heater from Topture is on the sauna heaters page.

Next steps for a sauna heater with rocks: electric, wood-burning or sizing help

Three routes narrow a sauna heater with rocks from here:

• Settled on electric heat: line up the electric heaters and their controls side by side under electric sauna heater packages.
• Heating with wood: narrow the stoves and their chimney parts under wood-burning sauna heater packages.
• Unsure which output suits the room, its glass or its supply: ask Topture's Lifetime Expert Support by phone at (833) 419-1774, live chat or email at contact@topture.com before you order.

Reviewed October 2026