Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Remove the retaining pin which holds the diverter motor in place, rest the motor on the boiler chassis in front of the diverter valve with the spindle facing upwards
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Press reset to cancel purge cycle countdown.
DHW demand.
Check the position of the spindle, it should extend fully for DHW operation.
Note:
The spindle rests in this position so may already be fully extended.