the boiler will not fire up when the tap is turned on unless the boiler is already lit for the central heating . However if you turn the tap on to full power it will sometimes light up when boiler not already on ... Seems to be a pressure of flow problem .. There are no fault lights showing at all . Any Ideas ??

JOANNA, February 2012

it sounds like your domestic diaphragm is worn or split, it's a ten minute job for someone who knows what their doing and the spare part is about £15.

mrboilerman, February 2012