Hot Tub Electrical Requirements

Hot Tub Electrical Requirements

Hot tub installation can get quite complicated. There are various safety aspects to consider, particularly when dealing with electrical connections.

The last thing anyone wants to do is get electrocuted - a definite possibility without understanding the basics.

Let's dive into what you should know about the electrical work required to install your hot tub safely!

Electrical Requirements For Hot Tubs

There are two different types of electrical connections for hot tub installation. As a rule, a licensed electrician should carry out all work involved in installing 220 to 240V hot spas. This includes all models not advertised as "plug-and-play". As a hot tub owner, you have a responsibility to ensure the electrical connections and hot tub wiring is be carried out by a licensed electrician, as per the National Electrical Code. There are also local code requirements that need to be adhered to when the hot tub is installed.

Remember, incorrect electrical installation can be dangerous, resulting in fire and property damage, electrocution, and death.

Plug-and-play spa installation is much simpler, minimal danger is involved, and can be performed by the hot tub owner themselves.

Let's dive in and cover each of your two options more thoroughly.

220V to 240V Hot Tubs

Also called hard-wired hot tubs, these models operate on a 220Vto 240V and 50A GFCI protected circuit. They feature a large water heater, usually 4 to 5.5 kW, and can heat up the water much more quickly compared to 110V hot tubs (commonly referred to as "plug-and-play" hot tubs).

Some models run on a higher current (60 to 100 amps). These are the hot tubs and swim spas that have multiple heaters or pumps for the jets. 

220V to 240V Hot Tubs

The dual-zone swim spas that have two separate temperature-controlled areas are a great example.

Although it's important to check the hot tub owner's manual for model-specific installation information, let's take a look at the typical electrical requirements and general precautions for the electrical installation of these types of hot tubs and swim spas.

Electrical connections

This has to be a 220V to 240V single phase, 4-wire electrical connection. The four wires include a white neutral wire, one green ground wire, and two live wires. Some hot tubs use a 3-wire electrical connection that features two live wires, one ground and no neutral wire.

Regardless of whether it's a 3 or 4-wire electrical connection, it has to be hard-wired to the terminals in the hot tub control box by an electrician.

A wire size of 6 AWG copper is recommended, however this could end up being bigger depending on the length of the wire required.

Disconnect Box

Roughly the size of a shoe box, the metal disconnect box must be installed in close proximity, between five and fifteen feet from the spa or hot tub, so that hot tub users can easily access it.

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Ground fault circuit interrupter (GFCI)

A ground fault circuit interrupter has to be used. The GFCI breaker is an important safety feature. It immediately closes off the power to the spa or hot tub if a fault from the supply conductors to ground occurs (if any water makes contact with the hot tub electrics).

A GFCI-protected circuit should also be used for all lights and electrical items utilized within a five-foot distance from the spa or hot tub.

Dedicated Electrical Circuit

The hot tub's electrical circuit should not be shared with any other electrical appliance. Don't be tempted to plug in your electric lawn mower or power tools into the same circuit.

This not only poses a hazard but it may trip the main breaker, which is a nuisance.

Electrical Installation Hazards

Incorrect wiring which can include picking a wire gauge of the wrong size and sub-optimal electrical connections can result in an electrical hazard.

At a minimum, it might just result in the annoyance of the GFCI tripping, but can also result in damage to the spa components and voiding of the hot tub warranty. The worst-case scenario can pose a serious health hazard to hot tub users such as electrocution.

Remember though, that a licensed electrician will be familiar with the National Electric Code and all other local electrical requirements and will ensure that these issues do not occur.

110V to 120V Hot Tubs


Also known as plug-and-play spas, these have far simpler electrical connections. They use a standard 15 to 20 amp home circuit, and can simply be plugged into a regular electrical socket.

You don't need an electrician and there are minimal electrical codes to follow, unlike for the hard-wired hot tub installation. Let's now explore plug-and-play hot tub electrical requirements.

Ground Fault Circuit Interrupter (GFCI)

For safety, most hot tub manufacturers include a GFCI breaker in the power cord that comes with the hot tub.

Dedicated Electrical Outlet

Plug-and-play spas must have a dedicated power socket that is not shared with anything else. If a shared circuit is used, then the circuit breaker may trip. Not only can this be a frustrating inconvenience, but also poses a safety hazard similar to the hard-wired spas previously explained.

Extension cables should never be used for 110V - 120V hot tubs.

If your home electrical service panel is not set up to accommodate running a hot tub, you may need to get an upgrade. If in doubt about the main panel, consult your local electrical service for a professional assessment.


One of the disadvantages of a plug-and-play spa is that you can't run all the jets and the water heater on full at the same time.

There is a way around this issue, however, you lose the portability aspect of this type of hot tub.

To get around this, a licensed electrician can convert a 110V to 120V plug-and-play hot tub to run on 220V to 240V, enabling the pump motor and water heater to be run on high simultaneously.

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About The Author

Meredith Kiley

Full-time staff writer at and stay-at-home mom.