The answer to your question is that you need a gas safe registered engineer to work on the boiler to find out. For gas safety reasons you are not allow to take even case off the boiler. Which will need to be done to locate the fault.
Anygasman
December 2009
or gas valve, twin solenoids aren't they?
ste
December 2009
pilot is not rectifying. faulty electrode, lead or pcb. most likely pcb on this boiler.
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