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 operate and reach maximum temperature.
Switch off CH demand.
Does the pump continue to run until the boiler has cooled down to approximately 80°C?
Note:
It may be necessary to reduce the heating load by turning off some radiators.
This will shorten the time required for this test.