OV9

En-suite shower is run from a pump. Pump is right next to the hot water tank and the two of them are literally - bar a partition wall - right next to the shower. There should be no problem with long runs of pipe / pressure loss etc.

Sometimes the pump won't run. When that happens there's a humming sound like it's powered but jammed. If you leave it like that it'll cut out (thermal overload ?) and stop humming for a minute or so then kick in and work perfectly. Other times it fires up no problem at all.

Is this a f**ked pump that needs to be binned, or something repairable ? Repairing is far preferable (not just the money, I'm very in favour of avoiding waste) but it's a PITA to get to the pump so I'd rather not go in there twice.

If it used to work it sounds like a knackered pump. Only other things it could be:

Header tank running dry due to a stuck ball valve but would be more likely to present as a shower that runs out rather than failing to start, or

It could be is air getting into the pump, but that would be down to how it’s piped up so can’t say really without seeing the install

But as said of it used to work it’s probably the pump

Jammed check-valve (non-return valve) was going to be my (completely unprofessional) guess. (Not even being sure if there was one in such a system). If the pump is buzzing it may be unable to flow if this is jammed closed? Sharp rap with a small persuader when the system is in this non-functioning condition might be worth a try.

Caveat: a wise man once said that a little knowledge is a dangerous thing.....

Hmm. Not aware of there being a non-return valve anywhere but that does sound feasible. Where would it be ? Near the pump, or near the shower ?

So annoying that it's intermittent. Makes me thing the pump is essentially OK but something is getting in the way.

jamcg wrote: Mon Aug 29, 2022 9:14 pm But as said of it used to work it’s probably the pump

Sometimes it works absolutely fine. That's what's annoying ! The pump works, just not every time.

The check valve is normally built into the flexible hoses coming off the pump or into the pump outlets

However as these things switch on based on water flow a check valve is unlikely, as you would get one side still pumping, so you’d have hot or cold at the shower and not both.