Independent comparisons. We may earn from shop links. More info

How to use a pool heater: hoses, then keep people out

Updated: 21 October 2026

You have either an Intex solar mat or the Bestway inline heater on the patio, and the first mistake is the hose order. How to use a pool heater, for these two machines, is a sequence: pump off, heater after the filter, nobody in the water while the electric element runs, and no coiled extension lead. This is not a ranking. If you have not chosen a type yet, start with the [pool heater buying guide](/hub/pool-care/pool-heater/sub/pool-heater-buying-guide). The nine listings are on the [Pool heater](/hub/pool-care/pool-heater) comparison. A qualifying purchase can earn us a commission at no extra cost to you. There was no lab heat test.

You have either an Intex solar mat or the Bestway inline heater on the patio, and the first mistake is the hose order.

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.Before any hose comes off
  2. 2.Connecting a solar mat
  3. 3.Running the Bestway inline heater
  4. 4.When to stop and who to call

Before any hose comes off

Turn the filter pump off before you loosen a hose. An open fitting on a running pump dumps water and can pull air when you start again. Lay the mat or the heater on flat ground, without a sharp bend. A kink is the flow failure UK reviews describe. For the Bestway, the socket comes before the plug. The 58259 manual wants a 30 mA RCD and says extension cords cannot be used. Test the RCD before each use. The heater belongs in zone 2 or outside the pool, on the ground, not in the water. If you are about to lower a mains rod into a pool someone is using, stop.

Connecting a solar mat

Intex puts the filter pump first and the solar heater last. Water leaves the pool, goes through the filter, then the mat, then back. The mat stays on the ground, not on a shed roof. Bypass it when you stop. Left in the circuit overnight, it sits in cold air, which is why some pools feel cooler by morning. There is no element. If flow dies, check a kink or a pump that has lost prime, then vent the pump. Support caps the pump under 5,678 litres per hour. The £24.49 bullet says under 7,570. Do not average them. Only that page states 32 mm points and 38 mm adapters. Sun against the element is electric pool heater vs solar mat.
Intex Intex solar mat 28685E

Testsieger

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

Running the Bestway inline heater

Plumb the Bestway after the filter. The pump moves the water. The heater only adds heat. Start the pump and confirm a return before you switch the heater on. It has no pump of its own. Test it before each use, on a 30 mA RCD, with no extension cord. Keep people out of the pool while it runs. The bullets state the RCD and the water sensor. The people-out line is in the manual. The listing claims around 1 °C an hour, up to a 40 °C cut-out. The manual’s band is about 0.5–1.5 °C an hour. There is no setpoint. A beep means the flow sensor is unhappy. A pump over 3,785 litres per hour, a kink or a blocked filter will stop flow. Do not defeat the sensor. If the RCD trips, stop, and do not keep resetting it.

When to stop and who to call

Stop if the plug is hot, the lead has melted, or anyone has had a shock. Unplug without touching a damaged pin, and do not run it again on the same lead. The Consumer Rights Act 2015 gives 30 days to reject goods that are not as described or not safe. That is a shop right, not a wiring design. Call an electrician for a new outdoor circuit, or if the 30 mA RCD will not test. A 2.8 kW load is about 12 A. This page will not draw that circuit. Before frost, drain the mat and the hoses. Do not leave the Bestway outside below 4 °C.

Common questions

Does the mat go before or after the filter?
After the filter. Intex’s connection note puts the filter pump first and the solar heater last, so the mat sees water that has already been filtered. Putting the mat first sends debris into the passages that kink and block. The same order applies to the Bestway: pump and filter, then the heater, then the return.
Can the mat sit on a shed roof?
No. Intex places the mat on the ground, not on a roof. A roof adds height, a bend at the edge, and a hose run the pump may not keep primed. If flow dies after you have raised the mat, bring it back to the ground and vent the pump before you add a second mat.
Can anyone stay in the pool while the Bestway is on?
No. The 58259 manual says not to run the heater while people are in the pool. The heater stays out of the water, in zone 2 or outside. The Amazon bullets do not repeat that sentence, so use the manual. This page does not describe a way to swim next to an immersion rod either.
Why does the Bestway beep?
The beep is the flow sensor, which UK reviews tie to flow stopping. A pump over 3,785 litres per hour, a kink, or a filter that needs cleaning will do it. It is not a thermostat announcing 40 °C. The 40 °C figure is a cut-out, not a beep you set. Do not bypass the sensor.
Why did the plug get hot on an extension lead?
The manual bans extension cords. A 2.8 kW load is about 12 A, and a lead left coiled on a reel is the pattern behind hot plugs and melted leads in the reviews. Use the RCD socket the manual asks for, with the lead uncoiled. If the plug has already melted, stop and do not refit the same lead.
What do I do with the mat before frost?
Drain it and the hoses, and store it where a freeze will not split the passages. Bypassing it is not the same as emptying it. The Bestway should not be left outside below 4 °C. A cover does not replace that drain.
Where does an electrician take over?
A new circuit, a socket you do not trust, a 30 mA RCD that will not test, or any doubt about the pool zone. Stop after a shock or a melted plug and report it. Do not design the cable yourself from a comment under the listing.

Related pages

Above ground pool heater

Pool heater

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

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

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)