Bestway filter pump air lock

Updated: 21 October 2026

The pump hums, the hose looks full of nothing, and the pool is as cloudy as it was yesterday.

The pump hums, the hose looks full of nothing, and the pool is as cloudy as it was yesterday. A Bestway filter pump air lock is the usual reason the water sits still after you have clipped the hoses on, and the fix is a short order: unplug, match the hose, bleed until water appears, then rinse the cartridge if the flow is still weak. This page follows Bestway’s own UK checks and the listings in our Bestway filter pump comparison. It is a procedure, not a ranking. Which pump fits the pool is on the buying guide. A qualifying purchase through our links can earn a commission at no extra cost to you.

Our top picks

Badge	Product	Hose	Air bleed	Cartridge	Note	Price	Offer
Best overall	Bestway Bestway 58383 cartridge filter pump	Two 32 mm hoses	Valve not stated	Type II 58094 included	7.6	about £49.99	View offer
Best value	Bestway Bestway 58381 cartridge filter pump	No adaptor; not 38 mm	Pressure-release valve stated	Type I 58093	7.4	about £37.49	View offer
Alternative	Bestway Bestway 58389 cartridge filter pump	Adaptors; 38 mm line conflicts	Valve not stated	Type III 58012	6.6	about £133.92	View offer

Best overall

Bestway Bestway 58383 cartridge filter pump

7.6/10about £49.99

View offer

Best value

Bestway Bestway 58381 cartridge filter pump

7.4/10about £37.49

View offer

Alternative

Bestway Bestway 58389 cartridge filter pump

6.6/10about £133.92

View offer

On this page

1.Unplug, then fit the hose you actually have
2.Bleed the air until water appears
3.Rinse or replace the cartridge
4.When to stop and call someone

Unplug, then fit the hose you actually have

Switch the pump off and take the plug out before you open the lid, pull a hose, or rinse anything. Bestway’s UK weak-flow page starts there. The 58381 says there is no adaptor and that the pump cannot connect to a 38 mm hose. The 58383 includes two 32 mm hoses and prints the same limit. Forcing a 38 mm hose onto either joint lets in air, and air is what stops the flow. The 58389 includes adaptors for 38 mm and 32 mm valves, and the same line also says it works only with 38 mm threaded valves. If the wall fitting does not match the sentence you are relying on, change the pump rather than taping the joint. Take the stopper plugs out, seat the hoses without a kink, and sit the pump on the ground below the waterline. Do not dry-run it on an empty pool. The shared review block says the supplied clips do not hold, so watch the joint for air.

Bleed the air until water appears

Bestway’s noisy-pump page is short. Open the air-purge valve, wait until water comes out, close the valve, and only then insert the plug. The 58389 manual says the same order, and it says to use a socket with an RCD. The 58381 listing states a built-in pressure-release valve. The 58383 listing does not state one, so do not assume that model prints the same part. If you cannot see a valve, follow the diagram on your own lid. Put the pump on the ground, below the waterline, and bleed again. Close the valve once you have a steady stream of water, not a spit of foam. Check the lid seal is seated before you restart, or the purge is undone.

Testsieger

Bestway Bestway 58383 cartridge filter pump

7.6/10about £49.99

View offer

Rinse or replace the cartridge

If water is moving and the pool stays dull, the next check is the cartridge, not a bigger pump. Unplug again. Lift the cartridge out and rinse it until the grey paste is gone. The 58381 bullet says clean or replace about every two weeks. Bestway’s UK article says about every 15 days. Those lines are the same kind of interval. They are not a timer. None of the five listings states a timer. The 58381 uses Type I cartridge 58093, and the listing does not say it is in the box. The 58383 title says a Type II cartridge 58094 is included. The 58389 names Type III cartridge 58012. A Type I refill will not fit a Type III housing. A gentle return is normal. Judge the pump by debris in the cartridge and clearer water over a day or two. Sand backwash stays on the cartridge versus sand page.

When to stop and call someone

Do not run the pump while anyone is in the pool. The 58389 manual says so. When swimming is over, you can start the filter again. If the RCD trips as soon as you insert the plug, stop. Resetting it in a loop is not a repair. If the cord is cut, crushed, or the plug is cracked, stop. Bestway says a damaged cord is not user-replaceable. Call an electrician for a new outdoor socket, a buried cable, a tripping RCD, or a damaged cord. Plug the pump straight into the mains socket, not through an extension lead. If the motor stops after days or weeks, that is a fault to return, not another afternoon of bleeding.

Common questions

What do I do before I open the lid?

Switch the pump off and unplug it. Bestway’s UK weak-flow checks start with that, before you rinse a cartridge or pull a hose. You are next to a pool with a mains pump, and the lid comes off only after the plug is out.

How do I bleed air out of a Bestway filter pump?

Open the air-purge valve and wait until water comes out, then close it, and only then put the plug in. The 58381 listing states a pressure-release valve. The 58383 listing does not state one. The pump should sit on the ground, below the waterline, or the bleed takes longer.

Why is water sitting in the hose and not moving?

Trapped air, a stopper plug still in the port, a kink, or a hose that does not match. The 58381 and the 58383 cannot connect to a 38 mm hose. Clips that do not hold, in the shared review block, let the joint suck air and the water stops.

Can I connect a 38 mm hose to the 58381 or the 58383?

No. Both listings say there is no adaptor and that the pump cannot connect to a 38 mm hose. The 58389 includes adaptors and also says, in the same included-components line, that it works only with 38 mm threaded valves. Match the fitting you have to the sentence on your listing.

Can I leave the pump running while someone is in the pool?

No. Do not run it with swimmers in the water. Start it again when everyone is out. If the RCD trips or the cord is damaged, stop and call an electrician. A damaged cord is not a home repair, and resetting a tripping RCD in a loop is not one either.

Bestway filter pump UK voltage