Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
Click HERE for information on PCB jumpers before carrying out test
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to ignite and run in central heating mode whilst monitoring the system pressure.
Is the heating operating satisfactorily?