Set Appliance State:

Gas Off
Isolate Mains Power to appliance as per TOPs P4
Remove the air intake from the fan
Disconnect the leads from the electrode assembly
Refit the ignition lead as shown to allow approx.
5mm gap between the lead and the electrode
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance as necessary and allow the boiler to complete its self check.
Shortly after the fan begins to run sparking should be observed for approximately 5 seconds between both leads and the electrodes.
This will repeat 5 times before boiler goes to ignition lockout.
Notes:
Ensure safe distance is kept from electrodes during test.
Do not refit the air intake after this test.