Set Appliance State:

Mains Power Off
CH Demand
Set Boiler Control Thermostat to MAX position
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).