my boiler was working fine, then the fan kept making a noise, and boiler would go off, it wud restart for short while if switched on and off. Eventually giving up alltogether, the fan bearings siezed, i replaced them with new ones, tested it by mains first before refitting, & it worked perfect. refitted & assembled boiler fan assembly. Switched on boiler and stat, fan worked immediatley, but boiler wud not ignite, all vacuum pipes r correct way round, as i made a note on dissassemble, along with wiring connections, boiler pressure is 1.5 bar, all pumps were ok before, along with hot water, any ideas out there please, thanks tone