Set Appliance State:

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

Observation:

This fault situation can often be remedied by performing a hard reset of the PCB.
Please perform the following steps before continuing:
Reset appliance by holding reset button in for 5 seconds then releasing.
Initiate a demand for heat by pressing the chimney sweep button for 3 seconds and then press again for 3 seconds after 30 seconds to cancel service mode.
Perform the above steps twice more so the boiler has been put into and taken out of service mode 3 times in total.
Please select from one of the options below:
BOILER RESETS - RETEST APPLIANCE
BOILER WILL NOT RESET AND REMAINS ON F0 FAULT CODE
BOILER HAS RESET, BUT F0 FAULT CODE HAS REOCCURRED