I have a gainsborough shower or my dad does anyway. recently it started not stoping on the water flow when switched off. Inside there appears to be a valve that switches off a main valve after a few seconds. I also noticed inside the case stuck to it what appears to be some washers three white ones. Having long ago lost the instruction manual I wonder if anyone knows anything concerning this. Its a 9.5KW gainsborough shower deluxe or that is what the label says.