Set Appliance State:

Mains Power Off
Gas Off
Turn Hot Water Tap On
Selector Switch in HOT WATER position
Combustion cover on
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Depress the Gas Control Knob. After a short boiler purge delay period (approx 20 seconds) the PCB should begin ignition and sparking should occur at the Spark Electrode.