Set Appliance State:

Mains Power Off
CH Demand
Turn Hot Water Tap On
DHW Temperature Selector set to MAX
CH Temperature Selector set to MAX
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Reset appliance as necessary.
Does the pump run?
Note:
Do not take noise or vibration as indication that the pump is running.
Pump Runs
Pump Does Not Run