Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
Selector Switch ON
Connect U gauge to pressure test point
Gas control knob in main burner position
Gas On; Pilot On
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow burner to ignite.
Does burner pressure rises to its set rate.
Notes:
The boiler is range rated for CH operation, the burner pressure should be set between 2.1 mb and 8 mb depending on system requirements. It is range rated by the potentiometers on the PCB, refer to Adapt for more information.
When U-gauge is removed pressure point should be tightened & checked for gas soundness.