Set Appliance State:

Gas Off
Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Remove the air intake from appliance
Disconnect the ignition leads from the
spark generator and make safe
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance as necessary and allow boiler to complete its self check.
Approximately 3 seconds after the boiler begins its ignition sequence,
can sparking now be heard from the spark generator?