Have a Potterton Suprima boiler which has worked well since the circuit board was replaced a few years ago.
Recently (and unrelated to the PCB lockout problem), on some occasions the ignition does not spread fully from right to left across the burner. Only one or two rows light up, resulting in lukewarm radiators. Sometimes the remaining rows ignite after a minute or two. Flames are blue and look healthy enough.
Boiler serviced months ago and is clean inside, including the burner which has been brushed and vacuumed to remove rust and dust.
Engineer booked but I'd like to arm myself with some ideas before he calls. It's an oldish boiler but I don't want to be persuaded to replace it just yet.
My suspicion is gas pressure problem.
Any ideas appreciated.
Recently (and unrelated to the PCB lockout problem), on some occasions the ignition does not spread fully from right to left across the burner. Only one or two rows light up, resulting in lukewarm radiators. Sometimes the remaining rows ignite after a minute or two. Flames are blue and look healthy enough.
Boiler serviced months ago and is clean inside, including the burner which has been brushed and vacuumed to remove rust and dust.
Engineer booked but I'd like to arm myself with some ideas before he calls. It's an oldish boiler but I don't want to be persuaded to replace it just yet.
My suspicion is gas pressure problem.
Any ideas appreciated.