Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Selector switch set to CH/DHW position
Boiler DHW thermostat set to MAX
Attach pressure gauge to burner pressure test point
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the burner to ignite.
The burner pressure should rise to approximately 4.5 mb, then over a
period of a few seconds ramp up to approximately 35.5 mb.
Note:
When pressure gauge is removed the pressure test point should be tightened and checked for gas tightness.