Set Appliance State:
Mains Power Off
Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4
Remove diverter valve microswitch cover
Remove diverter valve microswitch cover
Observation:
With the DHW tap fully open is the diverter valve spindle in its fully closed position (spindle fully retracted and actuator plate clear of L/H microswitch)?
Isolate as per TOPs P4
and refit as necessary