How Much Does It Cost to Run a Pool Heat Pump in the UK?
- heatpumps4poolsltd
- Dec 17, 2025
- 3 min read
if you've got a swimming pool in the UK, you know our weather isn't always kind to outdoor splashes. A heat pump can make all the difference, keeping the water lovely and warm without sending your electricity bill through the roof. But how much does it actually cost to run one? Let's break it down properly, with up-to-date figures for late 2025.
First Off, What's a Pool Heat Pump and Why Bother?
A swimming pool heat pump is basically an air-source gadget that pulls heat from the surrounding air and transfers it to your pool water. It's dead efficient compared to old-school electric heaters or gas boilers – we're talking 4-6 times more heat output for every unit of electricity you use. That's measured by the COP (Coefficient of Performance). A good one in typical UK conditions hits a COP of around 5, meaning for every 1kW of electric you chuck in, you get 5kW of heat out.
They're brilliant for extending the swimming season from May to September (or longer with a cover), and they're eco-friendlier too.
Current Electricity Prices in the UK (December 2025)
As of October to December 2025, the Ofgem energy price cap sets the average electricity unit rate at about 26.35p per kWh (including VAT) for direct debit customers. That's the capped rate most folks are on. Come January 2026, it'll nudge up slightly to around 27.7p per kWh, but for now, we'll use 26-27p as a ballpark.
Prices vary a bit by region and payment method, but this is a solid average.
We're number one... in unaffordable electricity — Institute of Economic Affairs
Typical Running Costs
It all depends on your pool size, how warm you want it, the outside temp, and whether you've got a pool cover (essential for keeping costs down!).
Average setup: For a typical outdoor pool (say 8x4m, around 30-40m³), a 10-15kW heat pump is common.
Daily runtime: In the swimming season, it might run 4-8 hours a day to maintain temperature (less in hot spells, more if it's chilly).
Power draw: With a COP of 5, a pump delivering 15kW of heat uses about 3kW of electricity per hour.
Rough calculation:
Electricity used per hour: 3kW
Cost per hour: 3kW × £0.2635 = about 80p
Running 6 hours a day: £4.80 per day
Over a month (30 days): £144
For a 6-month season (April-September): £800-£1,000
For smaller pools or with a good cover and inverter tech (which can push COP higher), you could halve that – down to £50-£80 a month in peak summer.
Older estimates from a couple of years back pegged it at £50-£60 a month for larger pools, but with current rates, expect a bit more unless you've got a super-efficient model.
Tips to Keep Costs Down
Get a pool cover – This is the big one. It stops heat escaping overnight and can slash running costs by 50-70%.
Go inverter – Modern inverter heat pumps adjust speed and can hit COPs of 6-7 (or higher in warm air), saving a packet.
Run it smart – Heat during the day when air's warmer (better COP), and use off-peak tariffs if you've got one.
Size it right – Too small and it'll run forever; too big and it's wasteful.
Maintenance – Keep filters clean and the unit clear of debris for peak efficiency.
Is It Worth It?
Absolutely, if you love your pool. Compared to gas heaters (which can cost double or triple to run) or straight electric resistors (eye-wateringly expensive), heat pumps are the cheapest way to heat a pool in the UK over time. Upfront cost is £2,000-£5,000 installed, but you'll recoup that in lower bills pretty quick.
If you're thinking of getting one, chat to a proper installer for a bespoke quote – they'll factor in your pool and location.
Fancy a dip without the dread of the bill? A heat pump's your best mate. Any questions, drop 'em below!
For more information, visit - https://heatpumps4pools.com/
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