Set Appliance State:

Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4
Attach U-gauge to gas valve outlet pressure test point
Hinge down front facia panel and set boiler to MAX
output setting using the gas valve mode switch
Boiler ON/OFF switch ON
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow boiler to commence its ignition sequence and ignite.
Observe the U-gauge, does the burner pressure increase to its MAX of 13.2mbar after approximately 5 seconds?
Notes:
1. When U-gauge is removed pressure test point should be tightened & checked for gas tightness.
2. If the burner does go to high flame, remember to set the boiler back to normal mode via the gas valve mode switch before continuing.