If the o/run stat is shorted on N/O and the gravity/pumped switch is on gravity this will give a P/L to the S/L on the board.
That is why I would be checking both. :wink:
I think either the pump o/run stat is U/S or if its since the fans been replaced, it is the fully pumped/gravity switch in the wrong position!
READ the M.I. and make sure this switch is in the correct position for your system.