12kW Sauna Heaters

Room size for a 12kW sauna heater

A 12kW sauna heater from this collection is HUUM's HIVE 12, which HUUM's US manual sizes for sauna rooms of 424–636 cubic feet (12–18 m³) on a 240 V supply. Before the room is matched to that range, HUUM's manual adds 3.3 cu ft to its volume for each square foot (1 m³ per m²) of uninsulated brick, tile or glass wall.

Decide on the HIVE 12 by the room's volume once HUUM's allowance is added:

• Inside HUUM's range for the HIVE 12: choose the HIVE 12, as the heater alone or as the 12kW package.
• Over 636 cu ft: rule out the HIVE 12. HUUM sizes the HIVE 15 for 530–813 cu ft and the HIVE 18 for 636–989 cu ft, both on 240 V, and the HIVE heater listing here sells both.
• Under 424 cu ft: rule out the HIVE 12 and size a smaller heater to the room instead.

12kW sauna heater supply: 240 V and HUUM's amps

HUUM's US manual lists the HIVE 12 for a 240 V supply at 50 amps. On the same 240 V supply, HUUM lists the HIVE 15 at 62.5 amps and the HIVE 18 at 75 amps.

For the UKU control that runs the HIVE, HUUM's UKU manual calls for a dedicated circuit and recommends new wiring, leaving conductor sizes to the heater's own manual; HUUM says only a licensed electrician may carry out that electrical work.

Choose the HIVE 12 over the HIVE 15 when a room of 530–636 cu ft sits inside both of HUUM's ranges and your supply cannot carry the HIVE 15's higher draw. Your licensed electrician sizes the breaker and wire from the manual that ships with the heater and your local code.

12kW sauna heater alone or in a package

The HUUM HIVE 12kW Electric Sauna Heater Package is Topture's combination of the HIVE 12 heater, a HUUM UKU control (UKU Local Black, or UKU Wi-Fi with a Black, Glass or Mirror panel), HUUM's UKU Extension Box and HUUM stones, sold as one item.

The HUUM HIVE Electric Sauna Heater sells the heater alone and ships without stones, though HUUM's manual says the heater requires them and the HIVE holds up to 551 lb (250 kg). HUUM's UKU control runs heaters up to 11 kW on its own, so the HIVE 12 needs HUUM's UKU Extension Box with it; the listing offers the UKU controls, the Extension Box and HUUM stones as add-ons.

• No UKU control or stones yet: choose the 12kW package.
• A UKU control or HUUM stones already on hand: choose the HIVE heater listing at 12 kW and add what it still needs from its product page.

Controls and Wi-Fi for a 12kW HUUM heater

Each 12kW heater here needs a separate control: HUUM's US manuals say its HIVE electric heaters have no built-in control. HUUM's electric heaters can be run from the HUUM mobile app through a UKU Wi-Fi control, while the UKU Local is run from its wall panel only, with no app. The UKU can be set up to 230°F (110°C), or 194°F (90°C) with its bench sensor fitted.

Choose a UKU Wi-Fi with a Black, Glass or Mirror panel if you want to run the HIVE 12 from the HUUM app; choose the UKU Local Black if a wall panel is all you need.

Topture is an authorized HUUM retailer, listed as an "E-shop" in HUUM's official dealer directory, and both 12kW listings here ship free within the contiguous United States; for more on buying a sauna heater from Topture, see sauna heaters.

12kW sauna heater next steps: another size or a sizing check

When the HIVE 12's room range or its draw rules it out for your sauna, or the room's volume is not settled yet, go next to:

• A room below the HIVE 12's range: compare heaters at the next output down.
• A room past the HIVE 12's range: compare 15kW sauna heaters.
• Room volume, glass or supply still open: Topture's Lifetime Expert Support checks the size with you by phone at (833) 419-1774, live chat or email at contact@topture.com.

Reviewed October 2026