Set Appliance State:

Mains Power Off
Gas On; Pilot On
CH Demand
Boiler Operating Switch in HW and CH position
Heating Control Thermostat adjusted to Maximum
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Operate the boiler in CH mode allowing it to obtain a high operating temperature.
Remove the CH demand.
Does the pump overrun?
Note 1:
Do not take sound or vibration as a sign of pump operation.
Note 2:
It may be necessary to reduce heating load by turning off some radiators to reduce time taken for this test.