Combi Boiler - No hot water

[TheRevelator80]

My combi boiler has ceased to produce hot water consistently. When the heating is on, there is intermittent hot water but when the heating is off there is none. It would appear that turning the hot water does not cause the pilot light to fire.

The boiler is a Halstead Ace High. Does anybody know what the likely cause of this is and what sort of cost I can expect.

Cheers

[gucciman]

its almost certainly a failed diaphragm in the diverter valve, i would be inclined to change the whole valve rather than just the diaphragm (dependant on whether the head of the valve that contains the diaphragm is easy or hard to get at). cost wise, halstead parts tend to be very expensive, to change the whole valve i would guess around £125, to change just the diaphragm around £75.