Does anyone have a circuit diagram for the Electronic control board (407677) used in these boilers. Mine is faulty and a diagram would make debug so much easier. I already tried relay replacement. It seems the fan is stopping preamaturely before sufficient pressure has been generated to operate the air pressure switch. I've replaced the air switch and checked the connecting pipes I've also checked the boiler cover seals. On most aoccasions the boiler does complete start-up, just occasionally it keeps cycling the fan for several minutes before eventually firing up.
- posted
19 years ago