Set Appliance State:

Gas Off
Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4
CH temperature selector to 0 position
DHW temperature selector to 0 position
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Reset lock out as necessary.
Allow appliance to self check and go to standby mode.
Sparking should occur approximately 2 to 5 seconds after the DHW temperature selector is turned on.
DHW temperature selector to maximum position.
Does sparking occur between the spark electrodes?