Set Appliance State:

Gas Off
CH Demand
Isolate Mains Power to appliance as per TOPs P4
Mode Switch in LOW position
Remove boiler inner case and combustion chamber cover
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the Fan to run, after a few seconds the boiler should run its ignition sequence and sparking should occur at the Electrode.