Sauna Electrical Requirements: 120V vs 240V

What the makers ask for

120V: the plug-in sauna

The Sun Home Solstice 2 draws 2,006 watts at 120V, about 17 amps. That is why it needs a 20-amp circuit to itself and a NEMA 5-20 outlet (the one with a sideways slot on one prong). On a shared bedroom circuit it will trip the breaker. Sun Home says to budget for an electrician unless a dedicated circuit is already where the cabin goes.

There are no 120V traditional heaters in the 6 kW class. At 120V, 6,000 watts would be 50 amps, which residential 120V circuits do not supply.

240V: a traditional heater

A 6 kW heater at 240V draws 25 amps. Circuits are sized with headroom, so the package listing asks for a 30-amp breaker and #10 copper wire. An 8 kW heater draws about 33 amps and asks for 40 amps and #8 wire. These are the same kind of circuits as an electric dryer or range. The heater size calculator tells you which heater your room needs.

What changes the electrician's quote:

• Distance from the panel. A backyard sauna 60 feet from the house means a trench and a long wire run. Redwood's heater listing recommends a heavier wire past 30 feet.
• Panel space. If your panel has no room for a two-pole breaker, or your service is already loaded with an EV charger and an electric range, the job grows.
• Permits. Many places require a permit for a new 240V circuit, and outdoor equipment can have its own rules. Ask your building department.

Before you order

1. Pick the heater size first (calculator).
2. Send the electrician the heater's model number and install manual, not just "a sauna."
3. Get the electrical quote before you buy the cabin. Two cabins $500 apart can end up $2,000 apart once wired.

Once it is wired, the running cost calculator estimates the monthly bill.

Common questions

Can a sauna run on 120V (110V)?

A small infrared cabin can. The Sun Home Solstice 2 draws 2,006 watts at 120V and needs its own 20-amp circuit with a NEMA 5-20 outlet. A traditional heater in the 6 kW class cannot, because at 120V it would draw 50 amps.

What size breaker does a sauna heater need?

Per Harvia KIP package listings, a 6 kW heater needs a 30-amp breaker and #10 copper wire, and an 8 kW heater needs a 40-amp breaker and #8 copper wire, both at 240V. Your heater's manual and local code decide the final size.