I am having problem with my combi boiler, {Halstead Ace High}. On opening the hot water tap, the boiler work fine but after 5 min running then burner goes off suddenly. I do not see any fault light on display /PCB either.
As the water turns cold and I turns the hot water tap off and on again. the boiler makessome checksbut fail to ignite. It appears that the pump is running. when theburner is off but no ventilation fan is not working either. Moving the control button to RESET button in 50% cases would reignite the burner. It appears that boiler is over heating and safety thermostat iscutting off yet ther is n't a lock out light as the Halsted fault finding diagram suggests.
Somebody in the trade suggestedto change the Air Pressure Switch. I have changed this APS but It has not solved the problem. after 10-15 minutes the boiler works again for anther 5-10 minutes.
Please suggest a solution for this misfiring of boiler.
thanks