Set Appliance State:

Mains Power Off
CH Demand
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.
It may take approximately 60 seconds for the boiler to recognise a CH demand after a DHW demand, this will depend upon the boiler status.
(Status code guidance CLICK HERE)