Set Appliance State:

Mains Power Off
Gas On; Pilot On
CH Demand
On/Off Switch in ON position
Mode selector switch to constant
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

Operate the Central Heating until the Boiler reaches its full operating temperature (i.e. burner shuts down) and then check that the pump continues to run.
Note:
It may be necessary to turn off some radiators to assist the boiler in reaching operating temperature and speed up the test.