CleverSpa heat pump & solar kit

A CleverSpa is one of the easiest ways to get a hot tub into a British back garden. They inflate in minutes, the app-based controls are genuinely friendly, and a good CleverSpa will happily seat four to six people on a summer evening. There's very little not to like — until the electricity bill lands.

The catch isn't the tub. It's the way it makes heat. Like almost every inflatable on the market, a CleverSpa warms the water with a built-in resistive element, and that single design choice is what makes these lovely tubs surprisingly thirsty to run — especially if you keep yours warm through a British winter.

This page explains why, and how a simple retrofit changes the numbers without asking you to give up the tub you already own.

Why CleverSpa tubs cost what they do to run

Inside your CleverSpa's heater box is a resistive heating element — the same basic idea as a kettle or an immersion heater. It's typically rated somewhere in the 1.5–3 kW range (check your specific model, as CleverSpa's line-up varies). Resistive heating is close to 100% efficient, which sounds great until you understand what it really means: every unit of electricity you buy turns into roughly one unit of heat, and not a scrap more. In heat-pump language that's a COP of 1.

You're paying full price for every kilowatt-hour of warmth. With the Ofgem price cap at about 26p/kWh (Ofgem cap, Jul–Sep 2026), that adds up quickly — the pump running, the water reheating after a soak, and the slow trickle of standby heat as a thin inflatable wall loses warmth to the night air. A CleverSpa isn't badly made; it's just doing the honest, inefficient thing that every resistive heater does.

What a CleverSpa costs to run

CleverSpa doesn't publish a single universal running cost, and we won't invent one for you — it depends on your model, your target temperature, how often you dip in, and how well your tub is insulated. As an industry comparator, it's worth looking at the figures a rival brand publishes for a similar inflatable tub:

• Lay-Z-Spa's own figures: roughly £0.60–£1.70 a day, or about £18–£50 a month.

Treat that as an optimistic, best-case manufacturer range rather than a promise — real winter running in the UK usually sits at the higher end or beyond. The important point is the shape of it: with a resistive heater, that whole bill is being charged at COP 1. Cut the electricity needed for the same warmth and the cost falls with it. For a figure grounded in your tub rather than a brochure, our UK hot-tub running-costs guide walks through what actually drives the number.

How our retrofit kit fits your CleverSpa

Eco Hot Tubs makes a retrofit kit — a UK-built, efficient air-source heat pump, with the option to add solar and battery storage — that bolts on to the CleverSpa you already own. You keep the tub, the liner, the seats and the app-driven convenience you bought it for. We simply take over the job of making the heat.

• Heat Pump Only — £895. The efficient heat source on its own, ideal if you're mainly chasing lower running costs from the grid.
• Full Eco Conversion Kit — £2,195 (founder price £1,845). Heat pump plus solar panel and battery, so more of your warmth comes from the sun and cheap off-peak power rather than peak-rate electricity.

It's designed for self-fit and works with essentially any inflatable CleverSpa model — the typical four-to-six-person sizes included. You're not replacing your hot tub. You're upgrading the least efficient part of it. Both products are currently offered on a reserve / enquiry basis rather than instant checkout, so we can confirm fit for your model before anything ships.

A CleverSpa that's genuinely clever about where its power comes from

The name promises smart; our kit delivers the part that actually saves money — a system that chooses its own energy source every time your tub calls for heat. At the heart of it is a smart switch box that swaps, automatically and safely, between your free solar and battery power and the household mains.

Here's the order it works to, without any input from you:

• Free solar straight from the 610W panel while the sun's out
• Stored battery power banked in the smart power box
• Cheap off-peak mains overnight to top up when needed
• Full-price mains only when there's no greener option left

The switching is seamless and protected — gentle start-ups, and a guard against the power dips and spikes that upset sensitive kit. Your CleverSpa carries on exactly as before; underneath, it's now sipping your own renewable energy first. Want to know which package suits your model? Drop us a message.

The heat-pump efficiency story — honestly

Here's the mechanism, without the marketing gloss. A resistive element makes heat from electricity at COP 1. An air-source heat pump doesn't make heat — it moves it, pulling warmth out of the outside air and pumping it into your water. Because moving heat is far cheaper than generating it, a heat pump can deliver a COP of around 3–5 in milder weather: the same warmth for roughly a third to a fifth of the electricity.

We won't pretend that holds all year. As the outside air gets colder there's less warmth to harvest, and efficiency drops — near freezing you're realistically looking at a COP of about 2–2.5. So think of it as roughly COP 2–3 across a real British winter, better in spring and autumn. Even at its winter worst, it's meaningfully more efficient than the resistive element it replaces.

Add the Full Eco Conversion Kit and the economics improve again. The battery lets you soak up solar during the day and store cheap Economy 7 / off-peak electricity — roughly a seven-hour overnight window at around 12.5p/kWh, about half the cap — then heat from that stored energy rather than pricey peak-rate grid power.

What will it save on my CleverSpa?

Honestly? It depends — on your model, your tariff, your target temperature and how cold your winter gets, so any single "you'll save £X a year" number would be made up. We'd rather show you a figure built on real inputs. We run this kit on our own tubs in the UK and monitor measured performance, and we've turned that into an interactive savings calculator where you can plug in your own numbers and see a realistic estimate for your CleverSpa.

Prefer to talk it through, or want us to check fit for your exact model first? Send us an enquiry and we'll come back to you plainly.

Hot water needn't cost the earth.

CleverSpa is a trademark of its owner; we are not affiliated — our kit is simply compatible with it.

CleverSpa retrofit — frequently asked questions

Will it work with my CleverSpa model?

The kit is built to suit the inflatable CleverSpa range in general, across the usual four-to-six-person sizes. Because heater boxes and connections vary, we confirm fit for your specific model when you enquire — that's part of why we run on a reserve basis rather than straight checkout.

Do I have to get rid of my current tub?

Not at all — that's the whole point. You keep your CleverSpa exactly as it is. The retrofit replaces how the water is heated, not the tub itself, so you don't lose the shell, the liner or the seating you already paid for.

Is the heat pump still worth it in winter?

Yes, though we're upfront that efficiency falls in the cold — closer to COP 2–2.5 near freezing rather than the 3–5 you'd see in milder weather. It's still more efficient than a resistive element year-round, and pairing it with the solar-and-battery kit to use cheap off-peak power helps most exactly when the weather is against you.