Zanussi
Fault Codes

Listed below are the common Zanussi fault codes as described by the boiler manufacturer along with a possible cause.

Zanussi Boiler Fault Codes

Fault Code	System Behaviour
C0	Boiler chip card (BCC) activation fault
C2	Boiler chip card (BCC) fault
F1	Low water pressure
F2	Flame loss
F3	Fan fault
F4	Flow thermistor
F5	Return thermistor
F6	Outside sensor failure
F7	Low mains voltage
F9	Unconfigured printed circuit board (PCB)
L1	Flow temperature overheat or no water flow
L2	Flame loss
L5	5 boiler resets in 15 minutes
L6	False flame lockout