Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Discharge and drain boiler
Remove wax capsule housing and wax capsule from the base of the diverter valve (1)

Observation:

Using a screwdriver or other suitable tool push up the diverter valve spindle then release.
Does valve spindle move up and down freely operating the microswitches on top of the diverter valve?