Set Appliance State:

Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4
Mode Selector Switch to DHW position
HW Temperature Control to Max
Attach a U-gauge to the pressure test point
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Measurement:

Burner pressure should be at a maximum 11.2 mbars.
After allowing boiler to heat up for at least 1 minute, slowly reduce the HW Temperature Control setting.
Burner pressure should reduce from approximately 11.2 mbars as control is turned down.
Note:
When pressure gauge is removed the pressure test point should be tightened and checked for gas tightness.