Set Appliance State:

Gas Off
Isolate Mains Power to appliance as per TOPs P4
Attach U-gauge to inlet pressure test point
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance as necessary and allow the boiler
to complete its self check.
Run the appliance in service mode
(hold down       button for 5 seconds until max is displayed).
Observe the U-gauge and press the       button once to extinguish the flame.
The gauge should return to standing pressure immediately as soon as the demand ceases.
Note:
Upon completing of the test the test point should be tightened and checked for gas soundness.