Set Appliance State:

CH Demand
CH Temperature control set to MAX
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance as necessary.
Can the burner be heard to ignite and establish?
Note:
The sparking on this appliance can be very quiet. If you are not sure if sparking is present click here for a test to check.