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 lockout as necessary.
With the hot water demand does the pump run?
Note:
If observation of pump shaft via removal of the vent plug is to be used to determine whether the pump is running care should be taken water does not penetrate the electrical parts of the appliance.