Sauna Heater Wiring Basics
Most of the time an electric sauna heater needs its own circuit from the panel. The first thing we want is the heater information, especially the size and the wattage, because that is what determines the circuit and the breaker size. Then the job is figuring out the best way to get from the panel to where the sauna is going and running that circuit.
Plug in vs hardwired and where controls can live
There are smaller heaters that are 120 volt plug in. If there is an outlet by the sauna, you can plug it into a normal outlet. But most installs still end up needing a dedicated circuit from the panel.
On controls, some heaters hardwire right into the heater itself. Some go to a controller first, like a little control board, so you can control temperature on the exterior of the sauna, then a wire goes from the controller to the sauna. Other heaters have the control right on the heater, a knob you turn up while you are in there. Those are factors that need to be figured out first.
Breaker sizing starts with wattage and amperage
Here is a concrete example. If it is a 9000 watt heater and it is a 240 volt heater, the math lands at about 37.5 amps. We need a breaker that is more than 37.5 amps, and in this case it goes on a 50 amp breaker. We also apply continuous load rules when they apply. If something is a continuous load, we take the load and multiply by 125 percent, then size the breaker off that. In this example, that puts it at 46.8 amps, so we go up to a 50 amp breaker.
Common breaker sizes and how we choose the next step up
Common breaker sizes come up often. For a 9000 watt sauna drawing about 37 amps, we would put it on a 40 amp breaker. If it is bigger and pulling more, we would probably put it on a 50 amp breaker.
Wire gauge must match the breaker
Breaker choice ties directly to wire size. If we put in a 50 amp breaker, we need a certain wire size, like number six wire gauge. For 40 amps, number eight gauge or so.
What happens when the breaker is undersized
If you have a 9000 watt heater and you put it on a 30 amp breaker, it is going to try to pull about 37 amps through that 30 amp breaker and it is going to trip every time. We size it according to the full maximum wattage that sauna heater can pull.
The common dangerous mistake when a breaker keeps tripping
If the wire is sized for a smaller breaker and someone upgrades the breaker to a bigger breaker to stop tripping, but does not upgrade the wire, you can burn up the wire because it is not rated to pull the higher amperage. If we upgrade the breaker, we upgrade the wire as well.
Why Homeowners Choose Mas Pro
Homeowners choose Mas Pro Service because we wire it correctly and safely. We run dedicated circuits when needed, size breakers and wire to the actual load, and route wiring cleanly from the panel to the equipment. Contact us for electrical wiring done the right way.
