How much does a hot tub cost to run in winter?

Winter is when a hot tub bill really bites. The water you're keeping warm is the same, but the cold air, the wind and the frozen ground are all pulling heat out faster than they do in July. So the heater runs more, and the meter turns harder.

Here's the honest picture of what a hot tub costs to run in a UK winter — across all five brands we support — why it climbs, how to bring it down, and the one change that keeps a tub efficient even in the cold. No invented annual figure; the real numbers are on the calculator.

Why winter costs 2–3× more than summer

Every popular inflatable and foam hot tub — Lay-Z-Spa, CleverSpa, Intex PureSpa, Wave Spa, Canadian Spa — uses a resistive heater. That means COP 1: one unit of electricity in, one unit of heat out, all year round. The heater doesn't get less efficient in winter. The tub just loses heat far faster, so the heater has to work more to stand still.

• Cold air. A bigger gap between your 38°C water and the outside temperature means faster heat loss.
• Wind. A breeze strips warmth off the cover and walls — an exposed tub loses noticeably more than a sheltered one.
• Cold ground. Heat drains straight down through the base into frozen earth or a cold patio, especially with no insulated mat underneath.
• Lid-off recovery. Every time you get in, the water cools, and in winter it takes far more energy to bring it back up.

Against COP 1, and with electricity at about 26p/kWh (Ofgem cap, Jul–Sep 2026), those hours add up quickly.

What the brands actually cost

They all use resistive heaters at roughly 1.5–2 kW, so in winter they behave much the same — the differences come down to insulation, cover and siting, not the badge (our guide to the cheapest hot tub to run in the UK ranks them by how well they hold heat). The most useful public anchor is Lay-Z-Spa's own published range: about £0.60–£1.70 a day, £4–£12 a week, £18–£50 a month. Treat those as the optimistic end — they assume light use, a decent cover and milder weather. Real winter use runs higher, and a bare single-skin tub left in the open in the cold can sit at the top of that range or beyond.

Lay-Z-Spa is a trademark of Bestway; we are not affiliated — our Lay-Z-Spa heat pump and solar kit is simply compatible with it. The same is true for CleverSpa, Intex PureSpa, Wave Spa and Canadian Spa. For the year-round breakdown behind these numbers, see our guide to hot tub running costs in the UK.

Cutting winter running costs (cheapest first)

• Upgrade the cover. A thick, well-sealed insulated cover is the single biggest lever — do this first, whatever heater you have.
• Insulate the base. A floor mat under the tub stops heat draining into cold ground.
• Add a windbreak. Move the tub somewhere sheltered, or put up a screen. Wind is a bigger thief than most people think.
• Ease the target temperature. Even a degree lower over a whole winter is meaningful, because you're holding a smaller gap against the cold.
• Heat on off-peak. On an Economy 7 or similar tariff the overnight window is roughly 12–15p/kWh, about half the day rate — though rates are supplier-set and vary. Heating in that window costs less for exactly the same warmth.

These help every tub. But they're all working around the same problem: a heater stuck at one-for-one. Our guide to the cheapest way to heat a hot tub goes deeper on each.

The real winter fix

The change that actually moves the needle is the heater itself. A hot tub heat pump stays efficient even when it's cold: it moves heat from the outside air rather than making it, so it uses a fraction of the electricity a resistive heater does. Its efficiency does dip in freezing weather — COP falling toward 2–3 from the 3–5 you'd see in milder months — but even at its winter worst it's using around a third to a half of what your built-in heater would.

Pair it with the rest of our renewable, app-automated system — solar panel, battery power box and smart switching — and the app fills the winter gap intelligently, leaning on stored solar and cheap off-peak mains when the sun's short (more on that in can you run a hot tub on solar power?). Nothing about how you use the tub changes. Just the bill.

What will you actually pay this winter? That depends on your tub, usage and tariff, which is exactly why we won't print a made-up figure. Try the savings calculator for a personalised estimate.

FAQ

Does a hot tub cost more to run in winter?

Yes — typically two to three times more than summer. The heater is no less efficient, but cold air, wind and cold ground pull heat out of the water much faster, so it has to run far more to hold temperature.

How much does a Lay-Z-Spa cost to run in winter?

Lay-Z-Spa's own published range is about £0.60–£1.70 a day, but treat that as the optimistic end — it assumes light use, a good cover and milder weather. In a real UK winter, expect the top of that range or beyond, because the cold, wind and frozen ground pull heat out faster. A heat pump conversion is what brings a winter Lay-Z-Spa bill down without changing the tub.

How do I cut winter running costs?

Start cheap: a thick insulated cover, a floor mat, a windbreak and a slightly lower target temperature. Heating on off-peak electricity helps too. The biggest structural saving is switching the resistive heater for a heat pump, which stays efficient even in the cold.

Can you use an inflatable hot tub in winter?

You can, and plenty of people do. Just expect higher running costs and slower reheats, and insulate hard — cover, base mat and shelter. A heat pump conversion makes winter use far more affordable without changing the tub itself.

Hot water needn't cost the earth, not even in January.