Set Appliance State:

Mains Power Off
CH Demand
Selector switch set to CH/DHW
CH temperature control set to MAX
Preheat switched OFF
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Does the pump run with a CH demand?
Note.
Do not take sound or vibration as a sign the pump is running.