what is the cause of a slight water leak from the front of the diaphram valve on the d.h.w.side. Leak is from where the plunger that makes the switch comes through the brass nut.The boiler is a glow-worm compact 80e combi boiler

Peter O'Hare, May 2006

This is a common problem, it is usually caused by a build up on the spindle causing the rubber seal to wear. you can replace the brass unit by turning the water off (black tap on 15mm pipe under boiler)and opening all the hot taps then undo the 4 screws and remove. Replace with new unit (around £20). Check that the water has not entered the microswitch, if in doubt replace this as well.

Ian, May 2006