Set Appliance State:

Mains Power Off
CH Demand
Set Boiler Control Thermostat to MAX position
Gas On
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Reset boiler as necessary.
Allow ignition sequence to commence and sparking to occur.
Does the burner ignite and establish? (Burner lit neon should illuminate).