Set Appliance State:

Mains Power Off
Turn Hot Water Tap On
Set flow rate to 10 litres a minute
Gas On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Allow burner to ignite and establish.
Allow the boiler to run for at least 2 minutes.
Does the same fault code reappear? (Shown to the right)
Does the heating flow pipe remain cold?
Note:
If a different fault code occurs click HERE to return to fault code page.