Set Appliance State:

Mains Power Off
CH Demand
User display control set to HW and CH
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Observe the boiler does it react and fire with the heating demand?
Note:
It may take up to 3 minutes to react and up to 5 minutes to fire due to a built in delay function.
This time can be reduced by turning the mains supply to the boiler off and then back on again.