Our old electric shower has finally given up - it's a roughy 10 year old Miralec unit that was there when I bough the flat so it may just have died of natural causes. It's been failing intermittently over the last few months, but has now been 'down' for two days.
The failure mode is as follows: it would work just for fine then suddenly stop, cutting the power and water. It would then remain non-functional for anything between a few minutes and a few hours. You just had to end your shower when it stopped and turn it off. Until the last failure, it would always resume working again later.
I did wonder if it was overheating, but the wide range of failure times suggests that may not be the case. The fact that the whole thing shuts down suggest to me it's the pressure switch that's cutting it all.
Sometimes there would be a gurgling sound from inside which would generally indicate that it was about to restart and I formed the impression that leaving the showerhead in the bath woiuld speed up this process. This led me to suspect that air was getting in to the system somehow.
There's an old style rotary valve as an isolator on the supply though this doesn't appear to actually shut off the water as I discovered while investigating the first failure. If this valve has failed could it be letting air into the system?
There is someting odd about our mains supply, in the kicthen the taps run striong for a few seconds after turning on than back off. I can't imagine this is related, but thought I'd mention it anyway,
Longer shot - the supply is shared with an upstairs flat. It tee's off to my shower and continues upstairs (a bit odd I know, but its a 1900 terrace and the plumbing has been munged a few times since then). My neighbours have recently had their bathroom redone, I can't think of anything their plumbers could have done to cause this, any suggestions?
The water supply is a surface mounted copper pipe which, although it's not pretty, I 'm going to retain rather when I replace the shower. I thought the easiest way to connect up the new shower would be a new service valve to replace the broken one and then a flexible hose to the shower. Any reason not to use a flexible hose - earthing issues perhaps?
Sorry for the long post.