Set Appliance State:

Gas Off
Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Remove the ignition lead cap from the spark electrode and place it near the spark electrode metalwork as shown
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to commence its ignition sequence.
Is sparking seen between the ignition lead cap and the metalwork?
Notes:
1. If it is not possible to position the ignition lead cap as shown position it so a spark is possible between the cap and the appliance metalwork - DO NOT hold the cap.
2. Reset ignition lockout as necessary until the outcome of the test has been determined.