Set Appliance State:

Mains Power Off
Boiler On
System calling for heat
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Look for signs of sparking through inspection window or listen for clicking sound from Full Sequence Board.
Note:
Ensure electrode is free from damage and there is a spark gap of 3-5mm positioned directly over the burner.