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Pool heat pump vs electric heater

Updated: 21 October 2026

You are choosing between a 2–3 kW plug-in heater and a heat-pump title that says 15 kW for a similar price. The pool heat pump vs electric heater decision follows from what each does with a unit of electricity. The five listings in the [pool heat pump comparison](/hub/pool-care/pool-heat-pump) do not state a COP, so they do not take the heat-pump side by default. Peter F. used Ofgem’s cap, SPATA and published specifications on 19 October 2026 and did not meter a pool. A qualifying purchase can earn a commission at no extra cost to you.

You are choosing between a 2–3 kW plug-in heater and a heat-pump title that says 15 kW for a similar price. The pool heat pump vs electric heater decision follows from what each does with a unit of electricity.

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.One kilowatt in, one kilowatt of heat
  2. 2.One kilowatt in, several kilowatts of heat
  3. 3.When the heater is the rational buy
  4. 4.When the heat pump wins, and which listings do not prove it

One kilowatt in, one kilowatt of heat

A resistance heater is an element in the flow, so its COP is about 1. A 2.8 kW unit draws about 2.8 kW and delivers about 2.8 kW of heat. B&Q’s listing of the Bestway 2.8 kW heater states 2,800 W at 20°C and warns against extension leads. A 13 A socket at 230 V supplies about 3 kW. At Ofgem’s Great Britain direct-debit cap of 26.32p per kWh from 1 October to 31 December 2026, 2.8 kW costs about 74p an hour. Northern Ireland is outside that cap. Amazon had a Bestway 2.8 kW heater, ASIN B0DHCH9H2K, at £139.99 with 3.3 from 121 reviews. It stayed out of this set because it is not a heat pump.

One kilowatt in, several kilowatts of heat

A pool heat pump uses electricity to move heat from outdoor air into the water. At a COP of 4, 1 kW in becomes about 4 kW of heat. SPATA puts a typical outdoor-season COP at about 3.5 to 4.5. An 8 kW heat output at COP 4 draws 2 kW and costs about 53p an hour at 26.32p, against 2.8 kW of heat for 74p from the element. Bestway’s 4 kW air-source manual, for a unit outside this comparison, states a COP of 4.8 at 26°C air and water. That is a warm-air line. The five kept listings cost about £154.44 to about £206.00 and claim 9 kW to 18 kW with COP not stated. A title near £180 is not evidence of a COP of 4.
JCKJWL JCKJWL 15 kW listing

Testsieger

JCKJWL JCKJWL 15 kW listing
5.8/10about £176.76
View offer

When the heater is the rational buy

Choose the resistance heater for a small pool, a hot tub, or occasional afternoons. Pool Warehouse points the same way: electric heat for a short top-up, and a heat pump for a season with a cover. Stay with the heater if you cannot name a COP, a coil and a supply. Paying about £176.76 for a 15 kW claim with one review and no COP is not a step up from a £139.99 element with a stated wattage. The best pool heat pump page says who should skip each of the five.

When the heat pump wins, and which listings do not prove it

Choose a documented heat pump when you will heat for hours across a season, with a cover on, and the sheet shows a COP around 4 at a temperature you swim in. Prices from about £599 for a small plug-in with a UK plug buy a lower cost per unit of heat. At COP 4, heat is about a quarter of the price of resistance heat. A 13 A socket is about 3 kW, and a 380 V unit needs an electrician. None of B0FBGRGG4J, B0FBGS476L, B0H678FS6D, B0DPM9X7M4 or B0FBGR4RX1 prints that COP. For a few hours on a small pool, buy the resistance heater.

Common questions

Is a heat pump always cheaper to run?
It is cheaper per unit of heat when the COP is real, around the 3.5 to 4.5 SPATA suggests for an outdoor season, and you need that heat for enough hours. At COP 4, 8 kW of heat is about 53p an hour at 26.32p, against about £2.11 an hour for the same heat from an element. A missing COP, a cold week, or an hour a week of swimming removes the advantage. The five cheap listings do not state a COP.
How much heat does a 2.8 kW electric heater make?
About 2.8 kW. A resistance element turns input into heat at roughly one to one. B&Q states 2,800 W for the Bestway unit at 20°C. At 26.32p on the Great Britain cap, that is about 74p an hour for about 2.8 kWh of heat. It does not become 15 kW because a neighbouring title says so.
When is the electric heater the better buy?
It is the better buy for a small above-ground pool, a hot tub, or occasional heating, when you want a known 13 A load and a low shelf price. A Bestway listing on amazon.co.uk was £139.99 and was left out because it is not a heat pump.
Can both run from a 13 A socket?
A 2–3 kW resistance heater can. A heat pump can if its electrical input fits in about 3 kW at 230 V. A 15 kW title might mean heat, which could fit, or electrical input, which cannot. The kept listings do not say which, and they do not show a BS 1363 plug. A 380 V variant cannot use a 13 A socket. Outdoor sockets still need a 30 mA RCD.
Do the £160 listings beat a £140 heater?
Not on the documents we have. The 2.8 kW class has a stated wattage. The heat-pump titles from about £154.44 to about £206.00 do not state COP, flow or a UK plug, and several contradict their own kilowatt figure. A true COP around 4 would beat the element over a season. These listings have not shown it. Keep the element until a page prints a 15°C test point.
What COP do I need before the heat pump wins?
You need a stated COP near 3.5 to 4.5, at an air temperature you will run, plus enough hours for the lower running cost to overtake the higher purchase price. At COP 4 the heat is about a quarter of the price of resistance heat. At COP 2 the advantage may never repay a seasonal cabinet. A COP that is not stated is not a COP of 4. A warm-air 4.8 at 26°C is not April.

Related pages

Pool heat pump running costs

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)