Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Refit combustion chamber if it was removed on previous test
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance as necessary.
Observe through boiler sight glass as the boiler
goes through its ignition sequence.
Shortly after the fan starts to run, is sparking present at the ignition electrode and does the burner ignite smoothly and establish?
Note:
Boiler will attempt to light 3 times before going to ignition lockout (solid red LED).