Set Appliance State:

Mains Power Off
CH Demand
ON/OFF Switch ON
Summer/Winter button set to Winter
CH Temperature selector to maximum
DHW Temperature selector to minimum
Ensure boiler is cool (run hot tap with gas turned off if necessary)
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Does the ignition sequence start and the burner ignite and establish?