My self-installed CH system has broken down after 11yrs fault-free running.
The system is sealed with a Danesmoor 20/25 RS floorstanding oil boiler controlled by a Honeywell Y plan. Firstly the 3-port valve motor failed, shutting down the system. I replaced the motor unit which fixed the problem for a few hours. Next symptom was boiler lock-out: resetting gets the fan running but lock-out again occurs after about 13 secs. There is oil arriving at the pump but no discharge; the photo cell is clean; there does not seem to be any spark at the igniter. I looked at the transformer and HT leads and found that the HT leads had been crossed since manufacture and had shorted out at the crossing point. I checked the transformer coils and found that both are not conducting.
I assume from these symptoms that the transformer has burnt out and since there is no ignition the fuel solenoid is not openning. If I am right a change of transformer and new HT leads should sort things out. Is this correct? Could other damage have occurred? Is there any other reason for this to happen? What else should I check?
Any help would be very welcome,
Many thanks in advance.
The system is sealed with a Danesmoor 20/25 RS floorstanding oil boiler controlled by a Honeywell Y plan. Firstly the 3-port valve motor failed, shutting down the system. I replaced the motor unit which fixed the problem for a few hours. Next symptom was boiler lock-out: resetting gets the fan running but lock-out again occurs after about 13 secs. There is oil arriving at the pump but no discharge; the photo cell is clean; there does not seem to be any spark at the igniter. I looked at the transformer and HT leads and found that the HT leads had been crossed since manufacture and had shorted out at the crossing point. I checked the transformer coils and found that both are not conducting.
I assume from these symptoms that the transformer has burnt out and since there is no ignition the fuel solenoid is not openning. If I am right a change of transformer and new HT leads should sort things out. Is this correct? Could other damage have occurred? Is there any other reason for this to happen? What else should I check?
Any help would be very welcome,
Many thanks in advance.