Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Remove diverter valve head from the body and place
in a safe location - do not disconnect it electrically
Boiler DHW thermostat to maximum position
Boiler CH thermostat to summer position
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the boiler to fire with the DHW demand.
Is the spindle fully retracted as shown?