I'm no expert but................. .......

It could be a spring inside the boiler which fires the boiler into life when the thermostat cuts in to heat the water. If the spring is worn it would fire the boiler and not cut off when it is supposed to. If it is this it would constantly blow the pilot light out because the pressure would rise to high. I will see if i can remember the name of the part. I'm not saying that is whats wrong with yours but its a possability. Does your pilot light go out often or do you constantly heat your water? Do you turn your boiler on/off at the elec mains a lot?

Posted By: CarlsbergCanary, Nov 11, 15:02:20