Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Remove pump vent screw
Take care to ensure any water released from the
pump centre screw is safely contained and cannot
get on to the appliances electrics
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Confirm the pump runs with demand?
(pump spindle rotates)
Note:
Do not take sound or vibration as a sign of the pump running.