Set Appliance State:

Mains Power Off
Turn Hot Water Tap On
Mains Isolator Switch (ON/OFF Switch) in ON position
Selector Switch in DHW Summer position
Hot Water Temperature Control set to Maximum
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Once burner has established, sparking should cease and burner should remain alight.
If the flame is not sensed within 10 seconds, the burner will go out and the lockout neon (Red) will illuminate.