My boiler is tripping out on over-temperature and it is the fan temperature cutout that is doing it. I have replaced the fan overheat thermostat, which has no effect.
When I remove the fan compartment cover, the fan casing is very hot to the touch and I can understand why it is cutting out. If I leave the fan compartment cover off, the boiler runs OK and the fan casing is cool to the touch. The fan is running.
Can anyone suggest what is causing the fan to over-heat? Following the Servicing Manual fault finding instructions, I end up replacing the PCB, which I am reluctant to do unless there is good reason to believe it is causing the problem. I can't see how the PCB could be causing the fan overheating but I would appreciate any comment or advice on the problem.
When I remove the fan compartment cover, the fan casing is very hot to the touch and I can understand why it is cutting out. If I leave the fan compartment cover off, the boiler runs OK and the fan casing is cool to the touch. The fan is running.
Can anyone suggest what is causing the fan to over-heat? Following the Servicing Manual fault finding instructions, I end up replacing the PCB, which I am reluctant to do unless there is good reason to believe it is causing the problem. I can't see how the PCB could be causing the fan overheating but I would appreciate any comment or advice on the problem.