Set Appliance State:

CH Demand
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to run for CH until the flow temp reaches approximately 50°C.
Remove CH demand.
Does the pump overrun after demand has ended for approximately 3.5 - 4.5 minutes?
Note:
To reduce the heating time some radiators can be turned off.