Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
DHW Demand
Remove spark lead from PCB and position above the spark generator on the PCB
DO NOT HOLD LEAD
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Allow fan to run and ignition sequence to commence.
Can sparking be seen on the board at spark generator.
Note:
Boiler may lockout during test and will have to be reset.