F codes are blocking faults, A codes are fault codes, however A or F may be displayed in front of any
number, it is the number that is most relevant and the tests followed will be the same for each.

Measurement:

Please select from the appropriate fault code below:
F04 Fume thermostat fault
F05 Fan fault
F07 Card parameter fault
F10 No 1 flow temperature sensor error
F11 DHW sensor error
F14 No 2 flow temperature sensor error
F20 Combustion control fault
F34 Power supply voltage low
F35 Power supply frequency error
F37 Low system water pressure
F39 Outside temperature sensor error
F42 Heating sensor fault
F43 Exchanger protection activated
F50 Gas valve fault