hiya, i have a biasi combi model no m90e 28s, the original problem was it was firing up for hot water but not for heating, now it's blowing the 13amp fuse in the power inlet switch,
cant tell with the limmited info but should not have 13 amp fuse in anyway 3 amp
tim
January 2009
yes i agree it could be the pump or the pcb. If you no a corgi reg plumber tell him/her to follow the wires from the pump to the pcb and disconect that coneector block. put a new fuse in and and turn on just for a few seconds and see if it blows. if it does its prob your pcb if not it is the pump
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