Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Remove the diverter valve motor from the body and place in a safe location so it can be easily observed
NO demands
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Observe the operation of the valve motor on initial start-up of the appliance it should move in and out by approximately 10mm, as shown in the animation below.
Note:
The appearance of the spindle may differ but the movement described remains the same.