Set Appliance State:

Mains Power Off
Set DHW temperature selector to MAX
Selector Switch to Hot Water and Heating
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Allow fan to run and ignition sequence to commence.
Observe through sight glass after approximately 10 seconds does sparking occur and burner ignite and establish for at least 10 seconds?