Set Appliance State:

Mains Power Off
CH Demand
Boiler On/Off Switch ON
CH Mode Switch in its 24hrs position
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

After operating the Boiler for several minutes in its CH mode remove the CH Demand.
Does the Pump overrun for approx 3 mins?
Note:
Do not take sound or vibration as a sign of pump operation.