Replacement Sauna Heaters

Electric vs. wood-burning replacement sauna heaters

A sauna heater replacement starts from what the sauna already has: an electrical supply for an electric sauna heater, or a chimney for a wood-burning sauna heater.

A wood-burning replacement stove is fired with wood rather than wired in, and HUUM describes its HIVE Wood as a choice for saunas without access to electrical connections. What a stove needs instead is a chimney its manual accepts: Harvia's M3 manual asks for a T600 chimney with a flue at least 4.3 in (110 mm) inside and rules out a shared flue, and HUUM's HIVE Flow manual says only a certified installation expert may connect the stove to the flue.

The heater already in the sauna narrows the replacement like this:

• Electric to electric. Choose an electric replacement if the sauna already runs an electric heater and its supply is one the new heater's maker lists.
• Wood to wood. Choose a stove that is loaded from the same side as the old one: Harvia's M3 is loaded from inside the sauna room, its M3 SL from another room or outside the building, and HUUM's LS stoves, installed through a non-combustible wall, from the next room.
• Changing fuel. If you switch from wood to electric, the sauna needs the supply the new heater's maker lists; if you switch from electric to wood, it needs a chimney and the floor protection the stove's manual asks for, such as the protective bedding Harvia's M3 manual calls for on a tile or combustible floor.

Replacement sauna heater output and room size

A replacement sauna heater is sized to the room, not to the heater it replaces: multiply the sauna's inside length, width and height in feet, then choose a model whose maker prints a minimum–maximum room range that covers the result.

Two heaters with the same output can carry different ranges: Harvia rates the KIP 6 kW for 170–300 cubic feet and HUUM the DROP 6 kW for 177–318, so a room just over 300 cubic feet is inside the DROP's range and past the KIP's.

Use the old heater's output to find where to start, then choose the replacement whose printed range covers your room and rule out any whose range stops short of it.

Glass and uninsulated walls in replacement heater sizing

Harvia, HUUM and Saunum each count glass and other uninsulated surfaces as extra room volume, by their own rules. Harvia adds about 3.9 cubic feet per square foot of uninsulated glass, brick, concrete or tile, counts a glass door, and multiplies a solid-log sauna's volume by 1.5. HUUM's US manuals for its CLIFF, STEEL and HIVE heaters add 3.3 cubic feet per square foot of uninsulated brick, tile or glass. Saunum's Air and Air L manuals add 3.0 cubic feet per square foot of glass, tile, brick, concrete or stone, multiply the room's volume by 1.5 when its log, plank or stave walls have no internal insulation, and point to the larger heater when the result falls between two sizes.

Electrical supply for an electric replacement heater

An electric replacement heater's supply and current are set by its maker, and they can differ from the old heater's: HUUM's US manual lists the DROP 6 kW at 25 amps and the DROP 9 kW at 37.5 amps on 240 V, and HUUM's UKU control manual asks for a dedicated circuit and recommends new wiring, with supply conductors sized as stated in the heater's manual.

The supply at the sauna narrows the replacement:

• 240 V. If the sauna has a 240 V supply, choose among heaters whose makers list one, such as Harvia's KIP with built-in controls, listed for 240 V single-phase, or HUUM's DROP.
• 208 V. If your building supplies 208 V, choose from HUUM's CLIFF and STEEL, which HUUM's US manuals rate for it, or from Harvia's three-phase versions of the stainless KIP with separate control (Harvia lists the black KIP for single-phase only), the Club and the 10.5 kW Virta and Virta Combi; Harvia lists the Virta Pro 20 kW for 208 V three-phase only.
• 120 V. If the sauna has only a 120 V supply, two heaters here run on it as well as on 240 V: Harvia's Vega Compact 1900, and the Amerec Junior 2.2 kW wired through Sauna360's contactor box and control. Both makers' manuals have them permanently installed and wired by a licensed electrician.

Topture's guide to sauna electrical requirements goes further into the circuit. Your licensed electrician sizes the breaker and wire from the manual that ships with the heater and your local code.

Replacement sauna heater brands: wall-mounted or floor-standing

Each maker's manual sets whether a replacement heater here hangs on the sauna wall or stands on the floor. Choose one that mounts the way the old heater did if the new heater has to take the same spot:

• Harvia. Choose Harvia's KIP, Spirit, The Wall or Vega Compact for a heater that hangs on the wall, or its Virta, Virta Combi, Virta Pro, Cilindro Half or Club for one that stands on the floor; Harvia's electric range is under Harvia electric sauna heaters.
• HUUM. Choose HUUM's DROP to hang a heater on the wall on its mounting frame, or the CLIFF, STEEL, HIVE or HIVE Mini, which stand on legs on the floor; the CLIFF Mini and STEEL Mini stand on legs and are also fixed to the wall with a special bracket. HUUM's electric range is under HUUM electric sauna heaters.
• Saunum. Rule out Saunum's Air and Air L if the corner between wall and ceiling above the heater cannot take Saunum's hot-air intake cap, or if you want to keep another maker's control: both stand on adjustable feet centred under that cap, and Saunum designs both to run only with its own Air IQ control.
• Amerec. Choose an Amerec Junior for a small room and a wall spot only if you already have Sauna360's contactor box and its SaunaLogic2 or H3 control: Sauna360 hangs both Junior heaters on a wall bracket screwed into a framing member or backing board, sizes the Junior 2.2 kW for 70–100 cubic feet and the Junior 3.0 kW for 100–150, and wires them through that box to the control; Topture sells neither control.

Sauna heater replacement costs beyond the heater: control, stones and chimney

A sauna heater replacement costs the heater's listed price plus whatever that listing leaves out. An electric heater carries its thermostat and timer on the heater itself or runs from a separate control unit, by its maker's design, and heater-only listings can ship without stones: Harvia's KIP and HUUM's DROP have none in the box.

• Keeping the old control. If the old wall control still works, choose a separate-control heater whose maker allows it: HUUM's manuals let the DROP, CLIFF, STEEL and HIVE Mini run from another certified sauna-heater control whose rated output covers the heater, and Harvia's manuals name its Xenio CX30 or CX45 control for the Spirit and the 6 kW Virta and separate-control Cilindro Half, while the 8, 9 and 10.5 kW Virta and separate-control Cilindro Half take the CX30 only on a two-group connection and the CX45 on a one- or two-group connection.
• No separate control. Choose a built-in model, such as Harvia's KIP with built-in controls, The Wall or the Vega Compact, if there is no wall control to reuse and you would rather have the thermostat and timer on the heater itself.
• Heater, control and stones in one order. To buy the heater with its stones and, where it needs one, its control as a single item, compare the electric sauna heater packages: Topture's HUUM DROP 4.5kW package, for one, combines the DROP 4 heater, a HUUM UKU control and HUUM stones.
• Wood stove and chimney. Harvia's M3 and HUUM's HIVE Flow ship without a chimney; for a stove with its chimney and stones in one order, choose from the wood-burning sauna heater packages, such as Topture's Harvia M3 kit with chimney and stones, which combines the M3, Harvia's WHP1500 chimney kit and Harvia stones.

Freight for every heater and heater package in this collection is included within the contiguous United States, and Topture's terms for buying a heater, from shipping to warranty coordination, are set out on the sauna heaters page.

Sauna heater replacement next steps: output pages, a new control or sizing help

What you know about the old heater picks one of three routes from this collection:

• By the old heater's output. If you know the old heater's rating, open the matching page, such as the 6kW sauna heaters or the 9kW sauna heaters, and keep the models whose printed range covers your room.
• A failed control. If the heater itself is sound and the fault is in its control, start with the sauna heater controls before replacing the heater.
• Sizing help. To check a replacement against your sauna before you order, send Topture's Lifetime Expert Support the old heater's model and the room's inside dimensions.

Reviewed October 2026