Set Appliance State:

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

Observation:

Tap reset button on the boiler display.
Does the boiler reset and enter standby (AP shown on display)
or does the fault code reoccur?
BOILER RESETS AND ENTERS STANDBY - RETEST APPLIANCE
BOILER REMAINS ON FAULT CODE
Note:
If fault is intermittent and keeps reoccurring select "boiler remains on fault code"