Before you start looking for a home sauna, you should make yourself aware of any electrical components you might need. This starts with understanding how a sauna is plugged in. This includes knowing whether it needs to be GFCI protected.
Short answer
Not automatically. The NEC has no sauna-specific GFCI rule. A plug-in 120 V sauna needs a GFCI outlet whenever the receptacle is in a location NEC 210.8 covers – bathroom, basement, garage, outdoors or within 6 ft of a sink. A hardwired 240 V sauna heater goes on its own dedicated two-pole breaker and needs GFCI only if the heater manual, a local amendment or your inspector requires it; several heater makers advise against GFCI breakers because moisture in the elements and the start-up current cause nuisance trips. Follow the manual (NEC 110.3(B) makes it binding) and have a licensed electrician do the hook-up.
Whether a sauna needs GFCI protection depends on the type of sauna and where it is installed. The US National Electrical Code (NEC) has no article written specifically for saunas. A plug-in 120 V sauna is treated like any other cord-and-plug appliance: its receptacle must be GFCI protected whenever it sits in a location NEC 210.8 lists, such as a bathroom, basement, garage, outdoors or within 6 ft of a sink. A hardwired 240 V heater runs on its own dedicated two-pole circuit sized to the heater (typically 30 to 60 A), and GFCI is required only where the heater’s manual, the local amendment or your inspector calls for it. Many heater manufacturers advise against GFCI breakers because the heater’s moisture and start-up current cause nuisance trips, and under NEC 110.3(B) the manufacturer’s instructions are binding.
Read on to determine if you need a special outlet for a sauna, the amount of energy it uses, and code requirements for having a sauna. Finally, discover the reason why your sauna keeps tripping.
Do you need a special outlet for a sauna?
The first step of owning a home sauna is plugging it in, but what are the requirements for the outlet used?
The general requirement of the outlet for a sauna is that it matches the sauna’s voltage and be GFCI protected. If purchasing a 240v sauna, the outlet must be 240v. This is often reserved for outlets where washing machines or larger appliances plug into. Also, the outlet must be dedicated to only the sauna. If not, it can overload the outlet.
Understanding the type of outlet you need is an important first step before purchasing a sauna. To make sure you have what you need, always check the voltage of the outlet you plan to use, and also check to see if it is GFCI protected. This can save you the hassle of having to upgrade the outlet after the fact.
Using an outlet that does not meet the set requirements can cause the following issues:
- Electrical Short
- Electrocution
- Damage to sauna
- Damage to other electrical devices
Read on to find out what a GFCI outlet is.
What is a GFCI outlet?
Before purchasing a GFCI outlet, find out what it stands for and how it benefits you.
A GFCI outlet, also known as a ground fault circuit interrupter, is designed to prevent electrocution. In short, it senses when someone is being shocked by electricity, then cuts off the power supply. GFCI outlets are primarily used outside or where the circuit may come into contact with water.
Continue reading to determine how much a sauna can increase your energy usage.
How much power does a sauna draw?
Power usage is another factor to consider before purchasing a home sauna.
Generally, the average amount of power a sauna draws is between 3 kWh (kilowatt per hour) and 7 kWh. However, this amount can fluctuate depending on the size of the sauna and the duration in which it is used. This can be determined by the wattage of the sauna. A 1,000-watt sauna is equal to roughly 1 kWh, a 2,000-watt sauna is equal to roughly 2 kWh, and so on.Â
Here is a table estimating the number of kilowatts a home sauna will use based on its capacity.
| Number of People | Average Kilowatts Used |
| 1 | 1.5 kWh |
| 2-3 | 3 kWh |
| 4-6 | 8 kWh |
Read on to find out how to wire a 240v sauna heater.
What about wiring a 240v sauna heater?
Instead of plugging it in, can you wire a 240v sauna heater?
Generally, some situations call for wiring a 240v sauna heater and it is a common practice. However, is best to not try this on your own if you are not a skilled electrician. There are certain code requirements for the wiring setup and wire used that must be met. Otherwise, it can cause harm to you, your sauna, or your house.
Continue reading to understand the code requirements for installing a sauna.
Sauna code requirements
Before installing a sauna, it is important to know and understand the code requirements for it.
For home saunas that you simply plug in, there are very few code requirements outside of the outlet matching the voltage and ensuring it is GFCI protected. However, if you are building a dedicated room that is a sauna, additional code requirements exist for the materials used in the room. This route often involves permits and city inspections.
Read on to find out the basic power supply requirements for a home sauna.
Sauna power supply
The code requirements for a sauna’s power supply are very simple.
Generally, the only code requirement for a sauna’s power supply is that it matches the voltage of the sauna itself. If the power supply is less than the sauna’s voltage, it can cause an electrical short. This can damage both the sauna and the electrical wiring in your home.
Read on to find out the basic circuit breaker requirements for a home sauna.
Sauna circuit breaker
There are two code requirements for a sauna’s circuit breaker.
A sauna heater needs its own dedicated circuit breaker, sized to the heater’s rated current plus the 25 percent margin the NEC applies to continuous loads (so a 6 kW, 240 V heater at 25 A lands on a 40 A two-pole breaker with 8 AWG copper wire). Whether that breaker also has to be a GFCI type is not fixed by the NEC: follow the heater manual first, then any local amendment, then your inspector. Where none of those requires it, most installers use a standard two-pole breaker, because GFCI breakers on sauna heaters are prone to nuisance tripping. A separate circuit also keeps a heater fault from taking down other rooms.
Continue reading to determine why your sauna keeps tripping.
Why does your sauna keep tripping?
After installing your sauna, you might have issues with it continuously tripping.
Your sauna might keep tripping because you have overloaded the outlet or the circuit breaker. First, make sure the voltage of the outlet matches the voltage of the sauna. Next, unplug any other devices you have plugged into the outlet. The outlet you use for your sauna should match the voltage and be a dedicated outlet for only the sauna.
For more info on this subject learn more about why your sauna is always tripping your breaker!
Sauna heater breaker and wire size (typical values)
These are the figures most 240 V heater manuals land on once the NEC’s 125 percent continuous-load factor is applied. They are a planning guide only: the number printed in your heater’s manual wins, and the run length, conduit fill and local amendments can push the wire up a size. Not sure which heater size you need in the first place? Use the sauna heater size calculator.
| Heater | Rated current (240 V) | Typical breaker | Typical copper wire | GFCI? |
|---|---|---|---|---|
| Plug-in infrared, 120 V, 1.5–1.8 kW | 13–15 A | Dedicated 15 or 20 A | 14 or 12 AWG (existing circuit) | Yes if the outlet is in a 210.8 location |
| 4.5 kW | 19 A | 30 A two-pole | 10 AWG | Per manual / inspector |
| 6 kW | 25 A | 40 A two-pole | 8 AWG | Per manual / inspector |
| 8 kW | 33 A | 50 A two-pole | 6 AWG | Per manual / inspector |
| 9 kW | 38 A | 50–60 A two-pole | 6 AWG | Per manual / inspector |
FAQ: Do saunas need to be GFCI protected?
Does a 240 V sauna heater need a GFCI breaker?
Not by the NEC alone. The code’s GFCI rules in 210.8 are written around receptacles and specific equipment such as pools and spas (Article 680), and saunas are not on either list. A hardwired heater therefore needs GFCI only when the manufacturer’s installation instructions, a state or city amendment, or the inspector signing off the job requires it. Because the instructions are enforceable under NEC 110.3(B), read the manual first: some brands prohibit GFCI breakers outright, others simply note that nuisance tripping is possible. Where nothing requires it, a standard two-pole breaker on a dedicated circuit is the usual installation.
Does a plug-in infrared sauna need a GFCI outlet?
Yes, whenever the outlet is in a place where the NEC already demands GFCI: bathrooms, unfinished basements, garages, outdoors, laundry areas and anywhere within 6 ft of a sink or tub. That covers most spots people put a one- or two-person infrared cabin. Use a dedicated 15 or 20 A circuit, plug the cabin straight into the wall (no extension cord or power strip), and if the GFCI trips repeatedly have an electrician measure the cabin’s leakage current before swapping anything. How much the cabin actually uses is in how much electricity an infrared sauna uses.
Why does my sauna keep tripping the GFCI?
Four common causes, in order of likelihood. First, moisture: heating elements absorb humidity when the sauna sits unused, and the small leakage current that creates trips a GFCI (which reacts to about 5 mA) even though the heater is sound; running the heater at a low setting for an hour often dries it out. Second, inrush current when all elements switch on at once. Third, a long cable run or a heater and lights sharing one GFCI, which adds up leakage. Fourth, a real fault such as a cracked element or water in a junction box. If the trip is instant every time, treat it as a fault and get it tested. The step-by-step checklist is in why does my sauna keep shutting off or tripping.
What size breaker does a sauna heater need?
Divide the heater’s wattage by its voltage to get the rated current, then multiply by 1.25 because a sauna heater is a continuous load, and round up to the next standard breaker. A 6 kW heater at 240 V draws 25 A, so 31 A after the margin, which lands on a 40 A two-pole breaker with 8 AWG copper; an 8 kW heater lands on 50 A with 6 AWG. The table above lists the common sizes, and the heater manual gives the exact figure the inspector will look for.
Do outdoor saunas need GFCI protection?
Any outdoor receptacle must be GFCI protected under NEC 210.8(A)(3), so a plug-in unit or the lighting and outlets inside an outdoor sauna cabin fall under it. For a hardwired outdoor heater the picture is the same as indoors: the NEC does not single it out, but inspectors require GFCI for outdoor heaters more often than for indoor ones, especially when the feed runs through a wet location or an outdoor sub-panel. Plan the circuit together with the building before you order the kit, see outdoor sauna plans.
Can I bypass a GFCI that keeps tripping?
No. Bypassing or jumpering a GFCI removes the one device that protects you from a shock in a damp room, and it voids the heater’s listing and most insurance cover. If the manual allows a standard breaker and the inspector agrees, an electrician can replace the GFCI breaker with an ordinary two-pole breaker on the dedicated circuit; if not, the fix is to find and remove the leakage source, not the protection.