The pilot light is burning...
The pilot sensor might not be hot enough to tell the control board that it's alight
The control board might be failing to "see" the signal from the pilot light sensor
The control board may be recognising the pilot is burning but failing to tell the main gas valve to open
The control board may be asking the gas valve to open but the gas valve assembly may be defective
A properly qualified engineer will be able to diagnose and repair your boiler
Peccavi, March 2009
