a 3 year old vitodens 100 suddenly stopped firing up on either water or heating, fault code F5 the book say's check fan & air pressure valve,
the fan is working ok,the valve test's ok but is not operating
can anyone give me a rough idea as to what the problem is .
the fan is working ok,the valve test's ok but is not operating
can anyone give me a rough idea as to what the problem is .