Hi, I have a glowworm 40ff boiler that is not firing, - the pilot light is there and its sparking but just not firing. it had been working intermittently but now just wont fire at all.

I have had an engineer look at it who said it was something to do with the voltage not being enough & he cleaned the contacts for something (I cant remeber what) and that seemed to work for a couple of months but not its gone again. I have just purchased a new pcb for the boiler but its made no difference!! Any ideas?

Thanks

Lee, October 2010

After doing some research, im thinking it could be the spark electrode so will try replacing this before calling engineer out

Lee, October 2010

could be the gas valve

b, October 2010