Mira Go leaking and won't switch off

Hi,



I have an old-shape (markings inside suggest 2002 manufacture) Mira Go electric shower in my bathroom, which was already fitted when I moved here and has never caused a problem in the 10 years I've owned the house.



However recently I went away for a few weeks and turned off the water supply in order to guard against frozen pipes. When I returned home and turned the water back on, the shower came on (even though the front panel switch was off) and began dripping rapidly from the join at the bottom of the case. The only way to stop the shower running was to turn the water supply off at the in-line valve on the pipe. When I opened up the case and turned the water back on, I could see that there was a thin trickle of water oozing from behind the flow valve assembly (no. 11 on the exploded diagram). There was however no flow from the head itself until I restored the power and pressed the switch.



I am therefore assuming that the flow valve has failed internally and probably that the water leak has damaged the switch and coil which is preventing the water supply to the shower head being shut off when the front panel switch is pressed to 'Stop'.



The cost of the new flow valve assembly (which conveniently includes the switch and solenoid) seems considerably less than that of replacing the shower (especially as Mira have changed the shape of the 'Go' model meaning it would no longer be a straight swap), and so I am thinking of having a go myself, but how difficult a job is this? I partly dismantled the shower whilst investigating the fault and it all seems pretty straightforward, but am wondering whether the replacement parts could be fitted with the unit in situ and the water supply connected, since whilst I am happy taking things apart I am not so confident in my plumbing abilities if it came to re-making the connection to the mains feed.



Thanks in advance for any assistance you are able to provide :)