Ideal Logic System IE fault codes

29 codes from the Ideal manual for the Logic System IE gas boiler. Pick one for what it means, the likely causes and where to start.

Code	What it means
F02	Flame loss
F04	Flow thermistor fault
F05	Return thermistor fault
F06	Outside sensor fault
F0D	Low water flow / low water pressure
F0T	Room thermostat fault
F0U	Flow/return differential greater than 50°C
F10	Spark generator fault
F12	Pump rotor blocked
F13	Pump fault
F15	Pump fault
F16	Gas valve fault
F17	Pump fault
F4	Control/no flow thermistor fault
F8	PCB unconfigured/faulty or gas valve short circuit
F9	PCB unconfigured/faulty or gas valve short circuit
FU	Differential greater than 50°C
L02	Ignition lockout after 5 attempts
L04	Flow thermistor fault
L05	Return thermistor fault
L06	False flame lockout / flame on before gas valve on
L0C	Repeated restart lockout
L0D	Ignition lockout: blocked flue/condensate
L2	Ignition lockout after 5 failed attempts
L4	Control/no flow thermistor fault
L7	Less than 5°C rise on 3 successive occasions
L8	PCB unconfigured/faulty or gas valve short circuit
L9	PCB unconfigured/faulty or gas valve short circuit
ON	Demand for heat present