Cheapest hot tub to run in the UK (2026)

If you're shopping for the cheapest hot tub to run in the UK, here's the honest starting point most guides skip: nearly every popular inflatable and foam tub uses the same kind of heater. A resistive element, COP 1 — one unit of electricity in, one unit of heat out. So the cost to make heat is much the same across brands.

What actually differs is how fast each tub loses that heat while it sits there. That's standby loss, and it's driven by the walls, the cover and the base — not the badge. So "cheapest to run" really means "best insulated". Here's our Top 10 — then why the order looks the way it does.

The 10 cheapest hot tubs to run

1. 1 Winner · Cheapest tub to run A hot tub run by a heat pump Uses a fraction of the electricity of any resistive tub — about a third to a fifth as much. See how → →
2. Every tub below uses a resistive heater — ranked by insulation
3. 2Canadian Spa MuskokaRigid closed-cell-foam acrylic hard-shell — the lowest standby heat loss of any tub here.
4. 3Lay-Z-Spa Carrara (ThermaCore)Rigid foam walls hold heat far better than a plain inflatable.
5. 4Wave Como (Eco Foam)Rigid foam walls — solid insulation for a pack-away tub.
6. 5Canadian Spa Swift Current V2Foam-wall portable — warmer to run than an inflatable of the same size.
7. 6Lay-Z-Spa EnergySense (AirJet)Inflatable with an insulating liner to cut some of the standby loss.
8. 7Wave AtlanticSingle-skin inflatable — leans on its cover to keep costs down.
9. 8Intex PureSpaSingle-skin Fiber-Tech walls — no foam layer to slow heat loss.
10. 9CleverSpaSingle-skin PVC inflatable — budget build, higher standby loss.
11. 10Lay-Z-Spa Miami (AirJet)Plain single-skin inflatable — the most heat to replace of the group.

Our best-guess order, ranked by insulation and construction — real-world running cost depends most on your cover and where the tub sits, and every resistive tub above sits far behind the heat pump.

Brand and model names are trademarks of their respective owners. Eco Hot Tubs is not affiliated with or endorsed by them.

Why insulation is the real difference

Because all these tubs heat at COP 1, the meaningful variable is heat retention. A well-built, well-covered tub holds its warmth, so the heater cycles less often. A thin single-skin tub with a bare base on cold ground leaks heat constantly, so the heater keeps kicking in. Same water, same target temperature, very different number of heating hours.

Be realistic, though: between resistive tubs the gaps are modest. Cover and siting swing the result more than the brand does. A good insulated cover is the single biggest lever — it's commonly cited as preventing up to around 70% of heat loss, an industry rule of thumb rather than a lab study. Our guide to the cheapest way to heat a hot tub covers those levers in order.

The honest small print

• The vendor efficiency numbers behind the ranking are manufacturer claims, not independent tests: Lay-Z-Spa says ThermaCore is "63% more energy-efficient than a regular PVC inflatable" (and up to 80% with a thermal cover); the EnergySense liner "up to 58%"; Wave says its foam is up to around 50% more thermally efficient. Useful for comparison, but treat them as the optimistic end.
• CleverSpa makes inflatable tubs only; its foam product is a floor mat accessory, not a foam-walled tub. Intex PureSpa is single-skin Fiber-Tech throughout — there's no foam-walled model. We mention this because plenty of listings blur it.
• An insulated base helps, but there's no reliable published figure for how much, so we won't invent one.

What the running-cost figures look like

Lay-Z-Spa's own published numbers are the best public anchor: about £0.60–£1.70 a day, £4–£12 a week, £18–£50 a month. A ThermaCore foam tub with a thermal cover is quoted "as little as 50p a day"; a plain Miami AirJet left in the open in cold weather nearer "£2–3 a day". Those assume light use — around 25 minutes, three times a week, in average summer conditions — so real and winter use runs higher. With electricity at about 26p/kWh (Ofgem cap, Jul–Sep 2026), the retention differences between tubs are real but, honestly, modest. Our hot tub running costs guide breaks the drivers down.

Why the heat pump wins by a mile

Here's the turn. Every tub in the list except the top one is stuck at COP 1, so even the best single-skin-to-foam upgrade still only slows the leak. The way to genuinely change the running cost — whatever tub you already own — is to change the heater.

A hot tub heat pump moves heat instead of making it, so it uses roughly a third to a fifth of the electricity of a resistive heater across the year, dropping toward a half on the coldest days (COP around 4–5 in mild weather, 2–3 near freezing). That's a bigger saving than the gap between the best-insulated and worst-insulated resistive tub — by a wide margin. It's why the honest answer to "cheapest hot tub to run" isn't a model at all. It's the heater.

Our heat pump retrofits to any of the brands above, and can grow into a fully renewable, app-automated system — solar panel, battery power box and smart switching that leans on sun and cheap off-peak mains (you can even run a hot tub on solar power this way), all run from an app that learns your habits. What that costs on your tub and tariff depends on how you use it, which is why we won't print a made-up figure. Try the savings calculator to see it for yourself.

FAQ

What is the cheapest hot tub to run in the UK?

Among resistive tubs, the best-insulated ones — rigid foam hard-shells, then foam-walled pack-away tubs — cost the least to run, because they lose heat slowest. But the gaps are modest, and cover and siting matter as much as construction. The genuinely cheapest option, whatever tub you own, is to swap the resistive heater for a heat pump.

What's the cheapest inflatable hot tub to run?

Among inflatables, an insulated-liner model like the Lay-Z-Spa EnergySense loses heat slower than a plain single-skin tub, so it's the cheapest of the pack-away inflatables to run — but only modestly, and a good cover on any inflatable narrows the gap. The bigger saving on any inflatable is swapping the resistive heater for a heat pump.

Are foam hot tubs cheaper to run than inflatables?

Generally yes, because foam walls slow standby heat loss — manufacturers claim roughly 50–63% less loss than a plain single-skin tub. Those are optimistic vendor figures, not independent tests, and a good cover on an inflatable narrows the gap. It's a real difference, just not a dramatic one.

Does the brand of hot tub really change the running cost?

Less than you'd think. Nearly all popular tubs use the same resistive heater at COP 1, so the cost to make heat is much the same. The difference is insulation and how you use the tub — cover, base and shelter swing it more than the badge on the side.

Hot water needn't cost the earth — whichever tub you already love.