My ravenheat boiler only provides hot water when the central heating is on.When you turn the taps on when the heating is off the boiler doesnt fire up and if it does it lights for a few seconds then cuts out.

stuartie, September 2008

normally this is the ch thermistor, under no circumstances should you turn off the isolation valves, they will leak when you turn them back on, also pilot assembly can cause this, if it is dirty, i would replace them both, while you are doing the pilot assembly disconnect the ht lead from the condensate trap (if it is csi range) this causes a lot of problems.

jay h, September 2008

needs new diaphram in diverter valve pin wont be activating the microswitch

jamie barrie, September 2008

Hi it will be the thermister, had the same problem, they are about £17, easy to fit, just turn off the taps under the boiler, then release the pressure in the sytem by turning the big red knob at the back of the water pressure gauge then unscrew the thermister a bit of water will escape put a new one on and try that

geoff, September 2008