Have a Trevi TT shower mixer valve in our en-suite. It has been out of action a couple of months or so whilst I got around to re-sealing the shower tray where there was a slight leak.
Re-sealing done, I've started using it again but noticed pretty much immediately that water won't always start to flow when the valve is turned on, and needs a sharp tap on the back of the valve body and it will spring into life (eventhough this is inset into the wall, I can get to it from the other side) and the pump will then fire up on from its flow switches as normal. Turn it on and off then, and it will behave itself - but come back to it the next morning, and usually the same problem.
Any ideas?
TIA, Midge