Set Appliance State:

Mains Power Off
CH Demand
CH temperature control set to MAX
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to ignite and run on central heating operation.
Is the heating operating satisfactorily?
Note.
During CH operation the chimney sweep led will illuminate green and blink off momentarily every 7 - 9 seconds to show the boiler is operating normally.