Thanks I'll try that, I've found out some more info on this and I think your right about the micro switch, I've had the whole thing apart, and put back together, It seems to have fixed this to a certain extent, but now the switch seems to fluctuate, ie the water coming thru the switch seems to judder, then if I turn the water back on then turn off slowly, it stops! It doesn't happen all the time, in fact quite infrequently, so going to live with this for now.
Mick Wells
September 2009