Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Turn Hot Water Tap On
Remove diverter valve head from the body
and position it so the spindle is visible
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Is the diverter valve in the DHW position?
(i.e. spindle fully extended)
Note.
It may take approximately 40 seconds for the boiler to recognise
a demand, this will depend upon the boiler status.
(Status code guidance CLICK HERE)