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Pool heater buying guide: type, volume, then the socket

Updated: 21 October 2026

You have a storable above-ground pool, and the amazon.co.uk aisle uses one name for three machines. This pool heater buying guide splits them before the stars. One is a 2.8 kW box after the filter. One is a mat that only adds heat in sun. One is a rod you lower into the water. The questions run type, then volume and pump flow, then the socket. The nine rows sit on the [Pool heater](/hub/pool-care/pool-heater) comparison. A qualifying purchase can earn us a commission at no extra cost to you. Prices and stars are the UK listing lines checked on 19 October 2026. There was no lab heat test.

You have a storable above-ground pool, and the amazon.co.uk aisle uses one name for three machines. This pool heater buying guide splits them before the stars. One is a 2.8 kW box after the filter.

Our top picks

Intex Intex solar mat 28685E

Best overall

Intex Intex solar mat 28685E
7.7/10about £24.49
View offer
Intex Intex solar mat 28685

Best value

Intex Intex solar mat 28685
7.6/10about £17.99
View offer
Bestway Bestway 2.8 kW inline heater

Rank 3

Bestway Bestway 2.8 kW inline heater
8.0/10about £139.99
View offer
On this page
  1. 1.Three things called a pool heater
  2. 2.Volume and pump flow
  3. 3.The socket before the heater
  4. 4.What to skip

Three things called a pool heater

An inline heater warms water the filter pump pushes through a box. Here that is only the Bestway at £139.99: 2.8 kW, an RCD, a water sensor, and a claim of around 1 °C an hour up to 40 °C. Amazon.co.uk shows 3.3 from 121 reviews. The Intex mats at £17.99 (3.7 from 11,021) and £24.49 (3.8 from 5,364) are about 1.2 m square, after the filter. Intex ties about 3–5 °C to the weather. There is no element. Only the £24.49 page states 32 mm points and adapters for 38 mm. Rods from £27.89 to £60.89 are a third object. The Ginger Tech at £28.99 is 3.0 from 39, with a hot plug and trips. With a filter pump, start with the mat or the Bestway. Who each listing is for is on best pool heater UK.

Volume and pump flow

The Bestway 58259 manual caps the heater at 3,785 litres per hour and aims it at pools of about 15 foot and smaller. Two copies disagree on volume: 17,035 litres and 18,930 litres. Do not average them. A larger pool is the wrong class for this box. A stronger pump is a mismatch. UK reviews describe a beep when flow stops, and the Amazon bullets do not print that cap. The Intex mat is for storable pools up to about 30,280 litres. Intex Support states a pump under 5,678 litres per hour. The £24.49 bullets state under 7,570 litres per hour, or up to 1/3 hp. Both figures exist. Do not pick a midpoint.
Intex Intex solar mat 28685E

Testsieger

Intex Intex solar mat 28685E
7.7/10about £24.49
View offer

The socket before the heater

A 2.8 kW load is about 12 A, near the top of a 13 A BS 1363 plug, for hours outdoors. The manual wants a 30 mA RCD, bans extension cords, and says not to run the heater while people are in the pool. The bullets state the RCD and the sensor, not the people-out line. BS 7671:2018+A2:2022 Regulation 411.3.3 requires 30 mA protection for outdoor equipment up to 32 A. A new circuit is an electrician’s job. NICEIC warns against a coiled extension lead. UK reviews name hot plugs and melted leads. Voltage is not stated on the listing. Ofgem’s Direct Debit average for 1 October to 31 December 2026 is 26.32 pence per kWh in England, Scotland and Wales, about 74 pence an hour at 2.8 kW. Northern Ireland is outside that average. The electric pool heater vs solar mat page holds the mat comparison.

What to skip

Skip a rod for a family frame pool. The Afenau, the SKJJM and the generic listing have no review line. The Hyunlai is 4.2 from 3. The VCYEX is 4.8 from 5, wattage not stated. Five reviews are not a larger sample than 121. Other immersion heaters have been recalled for shock. That recall does not test these ASINs. MC4, an A++ mark and a knife size are not hose sizes. Sand on the £24.49 material line is the same kind of field. A bullet that the cheaper mat will not work below 26 °C fights the 3–5 °C wording. Past the 15-foot aim, a heat pump is a different category.

Common questions

Do I buy the heater or the mat first?
Buy the type that matches the days you swim. Cloudy afternoons, on a pool of about 15 foot or smaller with a pump at or under 3,785 litres per hour, point to the Bestway. Sunny swims point to the £17.99 Intex mat, or the £24.49 listing if you need the hose sizes in print. A rod is not the first buy for a filter-pump pool.
What pool volume is the 2.8 kW unit actually for?
The Bestway 58259 manual aims at pools of about 15 foot and smaller. One copy states 17,035 litres and another states 18,930 litres. Both figures are in circulation, and they are not the same pool. The Amazon listing says above-ground pools and does not print either litre ceiling. If your pool is larger than both, look outside this heater.
What happens if my pump is stronger than 3,785 litres per hour?
The manual’s cap is 3,785 litres per hour. A stronger pump is the mismatch UK reviews describe, including a beep when flow stops. The Amazon bullets do not state that cap, so the manual is the document to read before you plumb it. Do not defeat the flow sensor to force a fit.
Do I need a cover as well as a heater?
Yes, if you want the degrees to last overnight. The Bestway claims around 1 °C an hour while it runs, and the manual’s band is about 0.5–1.5 °C an hour. An open pool loses that at the surface. SPATA treats a cover as the control on evaporation. The cover is not a substitute for a pump the heater will accept.
When is a heat pump the right category instead?
When the pool is larger than the Bestway’s 15-foot aim, or you want a long season rather than a few afternoon degrees. Do not copy a heat-pump kilowatt table onto this 2.8 kW resistance heater. Those tables assume a different machine. Leave this buying guide at the point where volume, flow or season no longer match.

Related pages

How to use a pool heater

Pool heater

Above ground pool heater: cover first, then a mat or 2.8 kW

Best pool heater UK: one inline heater and one sunny mat

Electric pool heater vs solar mat on a British summer

Sources

Public UK sources for the unit rate, the Bestway manual limits, outdoor RCD rules and the immersion-heater recall class, taken from the research digest. Listing prices, stars and review counts are from amazon.co.uk on 19 October 2026.

  1. Ofgem — changes to the energy price cap, 1 October to 31 December 2026 (retrieved 19 October 2026)
  2. Ofgem — energy price cap unit rates and standing charges (retrieved 19 October 2026)
  3. Bestway 58259 English manual (retrieved 19 October 2026)
  4. Bestway Flowclear 58259 manual, volume page (retrieved 19 October 2026)
  5. IET Wiring Matters — 30 mA RCD protection and regulation 411.3.3 (retrieved 19 October 2026)
  6. IET — Section 702, swimming pools and other basins (retrieved 19 October 2026)
  7. NICEIC — gardens and electrics (retrieved 19 October 2026)
  8. OPSS — product recall, Sorand water heater 2000 W (retrieved 19 October 2026)
  9. Intex — 47-inch solar mat (retrieved 19 October 2026)