Set Appliance State:

Turn Hot Water Tap On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow the appliance to run and reach operating temperature.
Test 1.
Measure the temperature of the hot water at the tap.
Record the result of the temperature measured.
Test 2.
Measure the temperature of the hot water as it leaves the boiler.
Measure on the pipe leaving the boiler (as indicated by the red arrow)
Record the result of the temperature measured.
Compare the two readings.
Is the temperature at the tap approximately the same as the output from the boiler or is it significantly cooler ?