Set Appliance State:

Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4
DHW temperature control set to maximum
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:

Appliance On/Off control set to ON position.
Reset lockout as necessary.
Allow the fan to run and ignition sequence to commence.
With a DHW demand is the burner pressure approximately as per the table?
Note:
When pressure gauge is removed pressure test point should be tightened and checked for gas soundness.