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Pool heat pump running costs

Updated: 21 October 2026

You want one electricity figure, and the honest answer is a range. Pool heat pump running costs move with the heat the water needs, the coefficient of performance that day, and whether a cover is on. This page uses the current Great Britain cap and does not pick a listing. The five titles in the [pool heat pump comparison](/hub/pool-care/pool-heat-pump) leave COP as not stated, so they cannot become a bill. Peter F. used Ofgem’s cap and SPATA’s factsheets on 19 October 2026 and did not meter a pool. A qualifying purchase can earn a commission at no extra cost to you.

You want one electricity figure, and the honest answer is a range. Pool heat pump running costs move with the heat the water needs, the coefficient of performance that day, and whether a cover is on.

Our top picks

JCKJWL JCKJWL 15 kW listing

Best overall

JCKJWL JCKJWL 15 kW listing
5.8/10about £176.76
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JCKJWL JCKJWL 9 kW variant

Best value

JCKJWL JCKJWL 9 kW variant
4.6/10about £163.00
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OUHFCASN OUHFCASN 18 kW 380 V

Alternative

OUHFCASN OUHFCASN 18 kW 380 V
4.2/10about £154.44
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On this page
  1. 1.Start from input kilowatts, not title kilowatts
  2. 2.Hours are the part nobody can promise
  3. 3.The cover changes the hours
  4. 4.How to read a shop’s seasonal table

Start from input kilowatts, not title kilowatts

The meter sees electrical input, not the kilowatts of heat in a title. Heat output divided by COP is the input. An 8 kW heat output at a COP of 4 draws 2 kW. Ofgem’s Great Britain direct-debit cap for 1 October to 31 December 2026 averages 26.32p per kWh, so two kilowatts for one hour is about 53p. Four hours is about £2.11. That 53p figure illustrates COP 4, inside SPATA’s outdoor-season range of about 3.5 to 4.5. It cannot be pinned to the about £154.44 to about £206.00 listings, because those pages do not state a COP. The same 8 kW from a resistance heater is about £2.11 an hour at 26.32p.

Hours are the part nobody can promise

Pence per hour become a day only when you know the hours. HeatPumps4Pools describes about 0–3 hours on a warm day once the pool is up to temperature, and 3–8 hours on a cooler day, with much longer running below about 5°C. Those bands assume a heat pump sized to the loss, not a cold start. SPATA says a first warm-up in under five days is generally unlikely when the unit is sized to ongoing loss. At about 53p an hour, three hours is about £1.58 and eight hours is about £4.22. Below about 5°C the air-source advantage shrinks and the hours rise together. Frost and draining sit on the pool heat pump installation page.
JCKJWL JCKJWL 15 kW listing

Testsieger

JCKJWL JCKJWL 15 kW listing
5.8/10about £176.76
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The cover changes the hours

Most heat leaves an outdoor pool as evaporation. SPATA estimates that an uncovered outdoor pool may lose about 90% of its heat that way, and that a cover can save as much as 80% of surface heat loss. The saving is fewer hours, not a different unit rate. The pump still costs about 53p an hour in the COP 4 example. It may run for one hour instead of four. Buy the cover before a larger compressor. GeoBubble later quoted 34p per kWh from a two-pool test. That is one manufacturer’s trial, not Ofgem’s cap. Use your tariff, and use 26.32p only as a dated benchmark.

How to read a shop’s seasonal table

A May-to-September table describes one pool. 1st Direct Pools has published figures down to about £50 for a very small pool across those months. Compass Pools’ £5 a day refers to their own 10 m by 4 m pool. The Wooden Pool Store’s worked example is 12 kW of heat for four hours at COP 6, about £1.92 at 24p per kWh. None of those totals is your bill, and 24p is not the October 2026 cap. Find the pool size, the cover, the COP with its air temperature, and the pence per kWh, or discard the total. Rebuilt at 26.32p, four hours at 2 kW cost about £2.11. This page will not invent a season bill for listings that print no COP.

Common questions

How much does a pool heat pump cost to run per day?
There is no single UK day rate. At 26.32p on the Great Britain direct-debit cap, 2 kW of input costs about 53p an hour, so four hours is about £2.11, excluding the standing charge. Three hours is about £1.58 and eight hours is about £4.22. Those hours are a shop guide for a warm day and a cooler day. Your pool, cover and COP move the result. Northern Ireland is outside this cap.
What unit rate should I use?
Use the rate on your tariff. As a public benchmark, Ofgem’s Great Britain direct-debit cap from 1 October to 31 December 2026 averages 26.32p per kWh, with a standing charge of 54.83p a day. Fixed deals differ. Leave the standing charge out of the heating sum, because you pay it anyway. A table still showing 24p describes an older price. A 34p figure from a cover trial is not the cap.
How many hours will it run?
HeatPumps4Pools suggests about 0–3 hours on a warm day and 3–8 hours on a cooler day once the pool is at temperature, and much longer below about 5°C. A cold start can take days. SPATA says a first warm-up in under five days is generally unlikely for a pump sized to the loss. With no COP on the listing, those hours still do not become a trustworthy bill.
How much does a cover change the bill?
It changes the hours. SPATA says most heat loss is evaporation, that an uncovered outdoor pool may lose about 90% of its heat that way, and that a cover can save as much as 80% of surface heat loss. The pence per hour stay the same. Fit the cover before you upsize the compressor.
Does the standing charge belong in the comparison?
On the Great Britain cap quoted here it is 54.83p a day, paid with the pump off. Adding it to both a heat pump and a resistance heater does not change which one uses fewer units. Mixing a heating-only sum with a bill that includes the standing charge is how totals drift. Northern Ireland and fixed tariffs use their own daily charge.
Why do shop tables disagree by hundreds of pounds?
They describe different pools, covers, COPs and unit rates. A very small covered pool can be published near £50 from May to September. A figure of £5 a day can be someone else’s 10 m by 4 m pool. Rebuild any total with your volume, your hours and your tariff. If the COP is missing, a 15 kW title cannot repair the table.

Related pages

Pool heat pump vs electric heater

Pool heat pump buying guide

Pool heat pump

Best pool heat pump UK: skip titles that omit a COP

How to install a pool heat pump: bypass, RCD, drain

Sources

Public UK sources for seasonal COP, grants, electrical rules and running cost, taken from the research digest. Listing prices, stars and review counts are from amazon.co.uk on 19 October 2026.

  1. Ofgem — Energy price cap, 1 October to 31 December 2026 (retrieved 19 October 2026)
  2. Boiler Upgrade Scheme Regulations 2022, regulation 9 (retrieved 19 October 2026)
  3. GPDO 2015, Class G — air source heat pumps (retrieved 19 October 2026)
  4. Approved Document P — electrical safety in dwellings (retrieved 19 October 2026)
  5. IET Wiring Matters — BS 7671 regulation 411.3.3 and 30 mA RCDs (retrieved 19 October 2026)
  6. GOV.UK — qualifications required to work on F-gas equipment (retrieved 19 October 2026)
  7. SPATA — swimming pool heating factsheet (retrieved 19 October 2026)
  8. Calorex 2025 inverter heat pump brochure (retrieved 19 October 2026)