Set Appliance State:

Mains Power Off
Turn Hot Water Tap On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance if required (rotate selector switch to OFF position for 4 seconds, then rotate back to DHW/CH position).
Does the pump run?
Note.
Do not take sound or vibration as a sign the pump is running.