Set Appliance State:

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

Observation:

Hold down the middle left button for approx. 10 seconds until bF is shown at the bottom left.
This resets the appliance to UK markets.
Apply a CH demand.
Allow burner to ignite and establish.
Does the fault code reoccur?