My Worcester boiler keeps locking out, about once every few weeks. Have had the thermistor sensor and overheat thermostat changed but it has done it again twice in the past two weeks.
At least I think it has, before these parts were replaced the lockout light flashed to indicate flame failure however the last two times this has occured, the lock out light has not flashed in fact the boiler demand light is steadily lit. By turning the temperature control off and then back on again striaght away the boiler fires up and all is fine.
Any suggestions as to what the problem might be. When the boiler is operating it is fine and provides great heat and hot water and when it locks out there is never a problem re-starting it. There is no trapped air in any of the radiators. There is no real trend as to when the boiler is doing this. Prior to the parts replaced it did it twice within an hour of coming on in the morning and the two times since the parts were replaced it has done it mid-afternoon.
