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Hot Tub Power Supply: What Electrical Requirements Do I Need?

Installing a modern hot tub is relatively straightforward, but that’s not to say there aren’t a few considerations you’ll need to make before firing one up! One question we’re often asked is what electrical requirements do I need to run my hot tub?

A lot of the standard tech inside hot tubs has changed and improved during the 10+ years we’ve been running this site. However, the electrical requirements needed to run a hot tub power supply safely have (for the most part) remained the same.

Hot Tub Power Requirements

Hard-shelled hot tubs generally use a 32A hard-wired power supply. This means the hot tub’s power cable must be hard-wired on its own fused spur directly into your home’s mains electrical system and cannot share a power supply with any other electrical appliances. 

A 32A hot tub can’t be plugged into a standard 3-pin plug socket, so you’ll need a professional electrician to install a dedicated outlet protected by a mains circuit breaker (MCB). This circuit should be designed to cover the max amperage of the spa (32A) + 25% to account for the initial rush of current when the hot tub is first powered on.

You’ll also need an IP65 Rotary Isolator Switch installed to safely cut the power supply during maintenance or in an emergency. This switch should be at least 2m away from the hot tub and run into a 6mm² 3-core SWA cable that leads to your spa’s pump unit.

Inflatable Hot Tub Power Requirements

a set of electrical wires

Inflatable hot tubs mostly rely on 13A power supplies. These lower amperage systems are popular as they’re less expensive to run and easier to install than 32A supplies. To safely use a 13A system, you’ll need a waterproof outdoor 3-pin plug socket with a built-in RCD unit.

This socket must be installed at least 2m away from your hot tub to avoid the risk of any water coming into contact with the live current. Choosing a socket with a sealable cover is also a good idea, as this will protect the device from water splashes and being tampered with.

Why an RCD is Essential

An RCD (residual current device) is essential as it will automatically switch off your electrical circuit in the event of a dangerous fault. This means if somebody touches a live wire or there is an electrical surge in your power supply, the current will cut out before it can do any harm.


Can you plug a hot tub into a standard socket?

Can any electrician wire a hot tub?

What if the spa plug becomes hot?

Last Word 

That just about covers the electrical requirements needed to run a hot tub safely. You’ll first need to determine whether your spa has a 32A or a 13A power supply. For a 13A system, you may already have a suitable outdoor socket, but it’s still wise to consult a professional to ensure your circuit won’t overheat! 

32A systems require a government-approved electrician to wire your hot tub to your mains electricity supply safely. And,  remember that for either scenario, your socket will need to be at least 2m away from where you intend to install your spa. With these bases covered, you’re all set to safely enjoy your hot tub!

John Devlin

Hello, Welcome to my website. I’m John, and I created the InflatableHotTubGuide while researching these spas nearly a decade ago. Since its creation, the site has become the leading UK resource for many models. As a passionate hot tub user, I love to test and explore all the latest machines this industry keeps creating. I hope you find our content helpful.