Set Appliance State:

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

Observation:

Attempt to reset the boiler.
(Control knob to off position then back to DHW & CH position)
Does the boiler reset and the fault code clear?
Please choose from one of the options below:
BOILER RESETS (RECHECK OPERATION)
BOILER WILL NOT RESET
BOILER RESETS BUT A DIFFERENT FAULT CODE IS SHOWN