Set Appliance State:
Gas Off
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
Access and move the X21 connector on the RHS of the PCB back
but do not remove it, so that the contacts on the PCB are visible
Disconnect the plug at the spark generator and make safe
but do not remove it, so that the contacts on the PCB are visible
Disconnect the plug at the spark generator and make safe
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the voltage between the brown wire at
connection X21 on the PCB to a suitable earth point.
Voltage should be approximately 155V DC.
Apply CH demand.
As the boiler reaches the sparking stage of the ignition
sequence the voltage should increase to approximately
400V DC or greater for 5 seconds before returning to 155V.
Note:
Voltage should increase 5 times until appliance locks out, reset and repeat test as necessary.
connection X21 on the PCB to a suitable earth point.
Voltage should be approximately 155V DC.
Apply CH demand.
As the boiler reaches the sparking stage of the ignition
sequence the voltage should increase to approximately
400V DC or greater for 5 seconds before returning to 155V.
Note:
Voltage should increase 5 times until appliance locks out, reset and repeat test as necessary.
Isolate as per TOPs P4
and refit as necessary