It's sort of working but without the pump to move the water away from the heat exchanger it will shut down due to overheat. Sounds like a diagnosis to me.
Peccavi, December 2009
just disconnected the pump upstair and now the boiler is working so is my pump gone??
seb, December 2009
usual suspects in order of sequence from boiler start on sys boiler, fan then gas valve.
if fan worked id suspect gas valve as its hopefully next in line of sequence
