Set Appliance State:

Turn Hot Water Tap On
Isolate Mains Power to appliance as per TOPs P4

Observation:

Is the DHW Flow regulating screw throttle correctly set?
Pass this test if the regulating screw cannot increase the flow rate above 2.8 litres/min.
Fail this test if the regulating screw can increase the flow rate above 2.8 litres/min