Published July 20, 2026 by National Electric NM
A hot tub is one of the larger electrical loads a home can add. Sorting out the wiring before delivery day saves a lot of frustration.
120 volt or 240 volt
Small plug-and-play tubs run on 120 volts and should have their own GFCI-protected circuit. Most full-size tubs need 240 volts on a 50 or 60 amp circuit. A 240 volt tub heats faster and can run the heater and jets together.
The disconnect
A hot tub needs an emergency disconnect that can be seen from the tub and is at least five feet from the water. For 240 volt tubs this is usually a small outdoor panel with a GFCI breaker.
Placement
- Keep the tub clear of overhead power lines.
- Leave access to the equipment compartment.
- Make sure the slab or deck can carry the filled weight.
- Think about the cable route from the panel. Shorter is cheaper.
Panel capacity
A 50 amp spa circuit is a significant addition. If your panel is full or small, you may need a sub panel or an upgrade. Your electrician will run a load calculation.
Leave it to an electrician
Spa wiring involves water, 240 volts, GFCI protection, and bonding rules, and it requires a permit. See hot tub electrical installation or learn about dedicated circuits.