Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Unclip diverter motor and place in a safe location where spindle can be observed
(pump may need to be pushed slightly upwards to allow removal)
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow ignition sequence to begin and burner to ignite and establish.
Is the diverter valve motor spindle in the DHW position - fully extended?