Question

We have fitted a new micro switch to our Reich Kama tap but now the water is coming out of the top of the tap when we switch on the power what have we done wrong

Answer

It sounds like you have disturbed the cartridge. If you removed the brass retaining nut to access the microswitch wire then you probably didn’t seat the cartridge back correctly. There are 2 lugs on the bottom of the cartridge which have corresponding holes on the casing of the tap, I would check these are located properly.