Set Appliance State:

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

Observation:

Attach temperature probes to the cold mains inlet
and DHW outlet, as close to the boiler as possible.
 
Allow boiler to ignite and run on DHW and monitor the temperature rise.
 
With a flow rate as per the table is there a temperature rise
of approximately 35°C and is operation satisfactory?
 
Note: If appliance has flow regulator fitted draw off rate will be below rate
          specified above. To investigate poor DHW flow click HERE