Hi
My trusty old Classic FF280 has stopped cross firing from pilot to main burner. The pilot light lights and stays lit. The fan is fully operational. The fault finding guide leads to a faulty gas valve. This also seems to be the diagnosis from checking the forum. Please can anyone confirm the diagnosis, could the pcb or the air pressure sensor also be the cause of the fault? I don't want to miss checking something, I need to get an engineer to fix asap and will order parts in advance of visit to help speed up the process.
I am also curious as to the mechanics of the valve and signals from the pcb. If the pcb has sent a signal to light the pilot, how does 1) the pcb identify the pilot is lit and 2) then advise the gas valve to send gas to the main burner? There is only one set of wires from the pcb to the gas valve that connects the pilot solenoid and to main gas valve via a bridged connector. There is power at both terminals of the bridge connector. There is a black wire in addition to the live and neutral wires, perhaps this provides a trigger for the main burner?
One last observation, the boiler used to fire up with a 'bang' rather than a smooth gradual flame increase. Maybe this gives a further clue to the cause of the problem.
Thank you in advance for your answers. Nicholas.
My trusty old Classic FF280 has stopped cross firing from pilot to main burner. The pilot light lights and stays lit. The fan is fully operational. The fault finding guide leads to a faulty gas valve. This also seems to be the diagnosis from checking the forum. Please can anyone confirm the diagnosis, could the pcb or the air pressure sensor also be the cause of the fault? I don't want to miss checking something, I need to get an engineer to fix asap and will order parts in advance of visit to help speed up the process.
I am also curious as to the mechanics of the valve and signals from the pcb. If the pcb has sent a signal to light the pilot, how does 1) the pcb identify the pilot is lit and 2) then advise the gas valve to send gas to the main burner? There is only one set of wires from the pcb to the gas valve that connects the pilot solenoid and to main gas valve via a bridged connector. There is power at both terminals of the bridge connector. There is a black wire in addition to the live and neutral wires, perhaps this provides a trigger for the main burner?
One last observation, the boiler used to fire up with a 'bang' rather than a smooth gradual flame increase. Maybe this gives a further clue to the cause of the problem.
Thank you in advance for your answers. Nicholas.