I offered to repair a combi boiler that had a diverter valve problem. The hot water side didn't work, but the heating side worked. I changed the Diaphragm in the diverter valve and the diverter now works. On re-starting the boiler, the pump starts when called to, but the pump flow switch doesn't start the flame lighting sequence (operates by the output of the pump on one side of a diaphragm and the input on the other). The water circulates and if the switch is switched on manually the boiler works ok and heats the water, also the hot water when called to. The pump motor is difficult to stall when dismantled. The pump flow diaphragm works when blown by mouth and doesn't leak. There doesn't seem to be any blockages and the components just fairly clean cnsidering.
Any ideas? EM
Any ideas? EM