Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
CH Demand
Selector switch set to CH/DHW position
Boiler CH thermostat set to MAX
Insert a link wire to bypass the external controls as indicated by the red wire
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Does the pump run ?
Note:
Do not take sound or vibration as an indication that the pump is running.