Set Appliance State:

Mains Power Off
Turn Hot Water Tap On
Preheat OFF
Ensure selector switch is in Hot Water position
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset boiler if required.
Listen for sparking and observe blue LED on front of boiler.
The LED will flash during the ignition sequence and then steady once a flame is detected.