[Closed] Misbehaving shower - anything obvious?

Sounds like thermostat problems

Looks like a fairly bog standard cheap thermostatic bar mixer. The thermostatic cartridge is probably on it's way out. You'll pick up an equivalent mixer only, for about 25 quid. Will take approx 5 mins to change it yourself. Just turn the water off first.
If that doesn't work, the pump is knackered. Approx 100 quid for a 1 bar pressure replacement. Again, something you could do easily yourself in 10 mins. Call out for the plumber would probably cost more than that

could be some debris in the inlet side of the pump or the back of the shower. check all filters before anything else

We've only been here a few months but believe that the shower/pump has only been in about a year (date on the pump seems to back this up) so would be a bit galling if it's failed already.

How could a faulty mixer bar stop it from pumping at all though, that's what's confusing me. The fact that adjusting the bar seems to "do" something to make it work does point to that though I guess.

Maybe I'll look into replacing the mixer bar wotsit then... Motivated by James May I *should* be able to do it, right?? Am I not a MAN?? 😉

All you need is a wide jaw adjustable spanner.
But as bear says, check the filter, you'll need to take the bar off the wall to do this, they should be just there wher the nuts are.

have you checked your airing cupboard for peadophiles? we had an infestation once and it turned out that they'd built a stack of hard drives powered directly from the immersion. should probably the first place to start if you ask me.

Hmmm, sounds like it could well be the thermostatic valve cartridge in the shower valve, but may also be a sticky/defective flow switch in the pump. Limescale can cause havoc with pumps, especially when they haven't been used in a while.

On my Stuart Turner, there is a reed switch on each of the outlets. How it works is there's a captive float inside the outlet pipe which contains a small magnet. When the shower valve is opened, water flow moves the float away from the reed switch and absence of the magnetiic field causes the it to make a circuit and this triggers the electronics to start the pump. There are two of these flow swithces, one on the hot and one on the cold. Flow detected on either should kick the pump into action.

Check out which pump you have and get the manual off the net. I'll guess it's a Stuart Turner, or a Salamander, but get the details off the pump. This manual may give some pointers on the symptoms you are experiencing. It could be an easy fix, but i'm not too hopeful of that. You have nothing to loose but a bit of time researching the problem.

If you aren't experienced in plumbing, I'd be a bit wary of dismantling the valve. You would need to isolate the supply pipes to the valve assembly before you remove it. If anything breaks it will be time consuming and potentially devastating (water can do a frightening amount of damage).

My advice, if reading up on the pump yields nothing, is to let a professional tackle it.

Just a thought is the supplies both from the same source/ pressure

in that you say that the pump is connected to the Mains ( cold water) and hot water tank.

Should you not have a balanced water pressure???

Should you not have a balanced water pressure???

Yes, you should! The hot water should be fed exclusively via and Essex or Surrey Flange off the Hot water cylinder. The Cold should be fed in the same diameter tubing from the cold water storage tank.

Spongebob thanks for the vote of confidance