My boiler switches on/off erratically. When HW tap runs, boiler sometimes switches on but cuts off right away. CH doesn't start at all.
I've changed the PCB, the display unit, the flame sensor (Slightly damaged). and the overheat control temperature sensor (Couldn't get recommended resistance reading)
The ignition electrode works OK and is in good condition .The boiler fires up nicely, but only for a couple seconds, after which I can hear a click in the gas valve area and an immediate shut down.
The reset button doesn't trigger anything when pressed. The HW indicator
(D) stays on, even when the CH room thermostat is triggered. with the pump running for a couple minutes before going back to neutral position (0). Then the cycle starts again, but not necessarily at regular intervals.
I checked the gas valve power supply (125volts),
the fan works OK
I checked the DWH thermistor resistance (11,000 Ohms reading, slightly above maximum recommended i.e. 10,300 ohms), checked the wiring but I didn't take it out to inspect it. should I have taken it out? Is there anything to "see" if the resistance is OK?
I checked the return temperature sensor (9,710 ohms, within range),
The diverter (Honeywell) seems to work as far as I can gather, but I'm not sure. The wiring is OK and the power supply as well, and when I switch the boiler on I can hear some clicks inside.
I'm running out of options and a nice hot bath would be nice! Has anyone got any suggestion? Have I omitted something obvious?
Hope to hear from one of you soon! Many thanks. Eric
I've changed the PCB, the display unit, the flame sensor (Slightly damaged). and the overheat control temperature sensor (Couldn't get recommended resistance reading)
The ignition electrode works OK and is in good condition .The boiler fires up nicely, but only for a couple seconds, after which I can hear a click in the gas valve area and an immediate shut down.
The reset button doesn't trigger anything when pressed. The HW indicator
(D) stays on, even when the CH room thermostat is triggered. with the pump running for a couple minutes before going back to neutral position (0). Then the cycle starts again, but not necessarily at regular intervals.
I checked the gas valve power supply (125volts),
the fan works OK
I checked the DWH thermistor resistance (11,000 Ohms reading, slightly above maximum recommended i.e. 10,300 ohms), checked the wiring but I didn't take it out to inspect it. should I have taken it out? Is there anything to "see" if the resistance is OK?
I checked the return temperature sensor (9,710 ohms, within range),
The diverter (Honeywell) seems to work as far as I can gather, but I'm not sure. The wiring is OK and the power supply as well, and when I switch the boiler on I can hear some clicks inside.
I'm running out of options and a nice hot bath would be nice! Has anyone got any suggestion? Have I omitted something obvious?
Hope to hear from one of you soon! Many thanks. Eric