The re-start button has the red light on, so when you press to manually start the boiler you can hear it sparking for a few seconds, a green light comes on and then the blue flame pops up, but then the sparking sounds quieter and then stops and the red light comes on. Could it be the spark generator !!
(Glow- worm inset fire with back boiler)

S Fenton, October 2007

It ended up being the gas valve !! as the problem.

Sean, March 2008

Hi Sean,
I got the thermostat - just over £10 & with me in a couple days. Installed it in about an hour all told. Up & running again (touch wood).

Pete, November 2007

Hi Pete, thanks for that advice , but I put a new board in and it still did not work, im told it is the gas control valve !!
I will keep you informed of what cures it.
As for your themostat,If its the one next to pcb they are about £10 plus vat from keep the heat on .com

Sean, November 2007

My BBU back boiler did this about 5 years ago. Ended up with a new PCB. Got one for about £80 online then about £30 for it fitting.
Stumbled across your question whilst troubleshooting a thermostat problem that I am now trying to sort.

Pete, October 2007