Hot tub electrics explained

13A plug-and-play vs 32A hardwired

Hot tubs come in two electrical flavours, and the difference shapes everything:

• 13A "plug-and-play" — inflatable and entry-level rigid tubs that run from a standard socket. Cheaper to get going and fine as far as they go, but the small heater is slow, and heat-or-jets compromises are common: run the bubbles and the water cools. Even these deserve a proper outdoor socket on an RCD-protected circuit — not a lead trailed out of the utility window.
• 32A hardwired — proper rigid tubs with 3kW-plus heaters and real pumps. These need their own dedicated circuit from the consumer unit, and it's not optional: the load is beyond anything a plug should carry for hours at a stretch.

Honest steer: if you're buying an inflatable to test the water, plug-and-play into a decent outdoor socket is a fair start. If you're investing in a rigid tub you'll use year-round, budget for the dedicated supply from day one — retrofitting it after the tub is sited and the patio is laid costs more.

What a proper 32A supply involves

• A dedicated circuit from your consumer unit, sized for the tub's full load, shared with nothing.
• SWA armoured cable to the tub — buried at a safe depth or clipped along walls and fences, built to survive spades, strimmers and standing water.
• 30mA RCD protection, so any fault current leaking to earth cuts the power in milliseconds. Around a tub of water, this is the single most important line on the spec sheet.
• A rotary isolator within sight of the tub — a weatherproof switch that kills the power locally for servicing, water changes or an emergency, without a march to the fuse box.
• IP-rated outdoor connections throughout, because every terminal lives outside in Fylde Coast weather — and the salt in the air this close to the sea corrodes bargain-grade fittings in a couple of seasons.

Why extension leads and hot tubs don't mix

Every summer we see it: a reel drum feeding an inflatable tub, warm to the touch by evening. A tub heater draws near a socket's limit for hours at a time — through an extension lead, especially a coiled one, that means heat build-up, melted sockets and in the worst cases fire. Add rain-soaked connections lying on the lawn beside a pool of water and it's the riskiest common shortcut in British gardens. If the lead is the plan, the plan needs changing.

Planning the run before the tub lands

• Site the tub before we quote — distance from the consumer unit drives cable size and cost more than any other factor.
• Think about the route — under lawn is an easy trench; under an established patio means lifting and relaying slabs. A wall-clipped run around the yard is often the tidy answer on Blackpool's terraced plots.
• Leave the isolator reachable — in sight of the tub but out of splashing range, and not behind where the cover lifts.
• Book the electrics before delivery week — a filled tub can't be nudged sideways to get a cable past it.

What it costs

Our hot tub electrical supply package is £500, covering the armoured cable run and an earth rod for the installation, with the dedicated circuit, RCD protection and isolator specified to your tub. This is notifiable work, so NAPIT certification is part of the job. Full details on our hot tub electrics page; if the same trench might carry garden lighting or an outdoor socket, our outdoor electrical prices show what's worth adding while the ground is open.

Commissioning day

Final connection into the tub's control box is usually done alongside the tub supplier's commissioning instructions — some brands want their own engineer to make the last connection to keep the warranty intact, others are happy for us to do it to their spec. Check which yours is before delivery day and we'll coordinate: supply live and tested before the water goes in, paperwork in your hand after.