I have the red flashing light, once per second. Went through manual fault finding. I replaced the spark electrode + harness, flame sensor + harness, PCB, APS and the gas valve, still to no avail. The fan and the pump kicks in and then when it requests a spark it just cuts out. I've had a qualified engineer look at it and he keeps going back to the PCB, but it's new, so we are both completely puzzled, has anyone got any other suggestions besides a sledge hammer?

Dave, October 2011

weve had a plumber out to ours same prob as you hes changed the fan red light still flashing now changed the ignition electrode it worked for one day then started flashing again paid £220 so far and still no hot water or heating.The plumber is stumped also!If someone has any idea what problem is please let us know!

ken, October 2011

Cheers Ian.
After fitting a new transformer, a friend mentioned the low pressure switch.
I took both leads off and joined them together and the boiler worked.
New low pressure switch required.

Dave, October 2011

check it's the correct pcb you have fitted, there are 2 for this boiler depending on the serial number.
if all else fails then call the manufacturer for a repair.

Ian, October 2011