Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
DHW demand from programmer
DHW temperature selector to high setting
Ensure hot water storage vessel is calling for heat
Remove diverter valve head from the body and place
in a safe location - do not disconnect it electrically
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?