Home sauna electrical requirements
Most traditional sauna heaters need a dedicated 240-volt circuit, typically on a 30 amp breaker for a 4.5 or 6 kW heater and 40 to 50 amps for larger ones, and the heater makers require a licensed electrician to wire them. Small infrared saunas for one or two people usually run on a dedicated 120-volt, 15 or 20 amp circuit.
Traditional heaters: amps and breakers
The figures below come from two common heater makers' US manuals. Breaker sizes are HUUM's; Harvia's manual gives the current draw and wire size but leaves the breaker to the electrician.
| Heater | Power at 240 V | Current | Breaker (HUUM) | Wire (Harvia KIP) | | --- | --- | --- | --- | --- | | 3 kW | 3.0 kW | 12.5 A | – | #12/2 | | 4.5 kW | 4.5 kW | 18.75–18.8 A | 30 A | #10/2 | | 6 kW | 6.0 kW | 25 A | 30 A | #10/2 | | 7.5 kW | 7.5 kW | 31.25 A | 40 A | – | | 8 kW | 8.0 kW | 33.3 A | – | #8/2 | | 9 kW | 9.0 kW | 37.5 A | 50 A | – |
Sources: HUUM DROP USA user manual, Harvia KIP heater manual (2023).
HUUM's manual notes that on a 208-volt supply the same heater puts out less heat: its 6 kW model delivers about 4.5 kW.
What the manuals require
- A licensed or certified electrician. Both HUUM and Harvia say the electrical work must be done by one, and Harvia says the warranty is void otherwise.
- Hard-wired, not plugged in. Harvia's manual says the heater must be permanently installed, with no plug or pigtail, and no outlets inside the sauna room.
- A standard 2-pole breaker. Harvia's manual specifies a standard 2-pole breaker and says not to use a GFI breaker on the heater circuit.
- Heat-rated cable. Harvia calls for 90°C (194°F) copper wire inside the sauna walls, and HUUM forbids ordinary PVC-insulated cable and requires an all-pole disconnect before the controller.
- Grounding to code. Harvia's manual says to ground the heater as required by the National Electrical Code and local codes.
Local rules decide whether you need a permit, so ask your electrician or your city's building department before you start.
Infrared saunas
Small infrared cabins draw far less power. Clearlight lists 120 volts and 15 amps for its 1-person models and 120 volts and 20 amps for its 2-person models, while its larger and outdoor models need 240 volts. Sunlighten's 2-person Amplify II draws 15.67 amps at 120 volts and needs a dedicated 20 amp circuit with a NEMA 5-20 outlet. (Clearlight, Sunlighten)
Infrared blankets plug into a normal household outlet. The HigherDOSE blanket draws 4 to 5 amps. (Bluemercury)
Lights and controls
Barrel and indoor kits often need a separate 110–120 volt, 15 amp line for the light, as listed for the Almost Heaven Salem and Grayson. (SaunaPlace)
Once it is wired, see what it costs to run with the sauna running cost calculator.
Frequently asked questions
Does a home sauna need 240V?
Traditional sauna heaters of 4.5 kW and up need 240 volts. Small 1- and 2-person infrared saunas usually run on a dedicated 120-volt circuit, and infrared blankets plug into a normal outlet.
What size breaker do I need for a 6 kW sauna heater?
HUUM's US manual lists a 30 amp breaker for its 6 kW heater at 240 volts, which draws 25 amps. Your electrician sizes the breaker for your heater and local code.
Can I plug a sauna into a regular outlet?
Only small infrared saunas and blankets. Harvia's manual says traditional heaters must be hard-wired, with no plug.