Daikin Fault Codes
Indoor Fault Codes
Fault Code Definition Supposed Causes Split Skyair VRV Package
A0 | External protection active | External protection wired to T1-T2 active |
A1 | Failure of indoor PCB | Defect of PCB or noise |
A3 | High water level | Float switch open circuit |
A5 | HP control in heating or freeze protection in cooling | Poor airflow, short circuit, EEV, refrigerant charge, indoor coil sensor incorrect value |
A6 | Fan motor failure | Locked, over current, over load |
A7 | Failure of louvre motor | Louvre motor/indoor PCB failed |
A8 | Failure of power supply | Over current of AC input, defect of supply |
A9 | EEV failure | Defect of EEV motor, indoor PCB |
AF | High water level | Float switch open circuit while thermo off |
AH | Failure of dust collector | Defect of dust collecting element, PCB |
AJ | Capacity setting error | Capacity setting adaptor missing |
C1 | Communication failure. Between main-sub PCB | Failure of communication fan motor control driver |
C4 | Indoor coil sensor | Open/short circuit |
C5 | Suction pipe sensor | Open/short circuit |
C6 | Failure of fan motor driver | Defect of fan motor sensor, control driver |
C7 | Front panel driving motor fault | Defect of limit switch, front panel driving motor |
C9 | Return air sensor fault | Return air sensor open/short circuit |
CA | Discharge air sensor fault | Discharge air sensor open/short circuit |
CC | Failure of humidity sensor | Failed humidity sensor |
CJ | Failure of remote sensor | Defect of remote controller sensor |
Daikin Fault Codes
Outdoor Fault Codes
Fault Code Definition Supposed Causes Split Skyair VRV Package
E0 | Protection devices tripped | Outdoor safety device tripped |
E1 | Failure of outdoor PCB | Defect of PCB or noise |
E3 | High pressure | High pressure switch tripped |
E4 | Low pressure | Low pressure switch tripped |
E5 | Inverter compressor lock | Inverter compressor locked |
E5 | Inverter compressor to hot | Compressor windings too hot |
E6 | DOL compressor locked | High current draw |
E7 | Fan motor failure | Failed fan motor, PCB |
E8 | Inv compressor high current | Compressor, PCB |
E9 | EEV motor failure | EEV motor, PCB |
EA | 4-way valve failure | Defect of valve, PCB, sensor |
EC | Inlet water temperature | Abnormal water temperature |
EF | Thermal storage unit defect | Thermal storage EEV, PCB, sensor |
F3 | High discharge temperature | Discharge temperature over 110°C |
F6 | High pressure in cooling | Detected by outdoor coil sensor |
F6 | Over charged | Refrigerant over charge |
H0 | Compressor sensor system | All sensors disconnected |
H1 | Failure of humidifier damper | Defect of limit switch/damper |
H3 | Failure of hp switch | High pressure switch open circuit |
H4 | Failure of lp switch | Low pressure switch open circuit |
H5 | Failure of compressor sensor | Defect of compressor overload sensor |
H6 | Compressor position failure | Position detection error |
H7 | Failure of fan motor signal | Defect of fan motor, PCB |
H8 | Compressor input error | Defect of transistor, PCB, reactor |
H9 | Failed ambient sensor | Sensor open short circuit |
J1 | Failed pressure sensor | Pressure sensor failed |
J2 | Failed current sensor | Defect of current sensor, PCB, compressor |
J3 | Failed discharge pipe sensor | Discharge pipe sensor open/short circuit |
J4 | Failed outdoor coil vapour sensor | Sensor open/short circuit |
J5 | Failed suction pipe sensor | Sensor open/short circuit |
J6 | Failed outdoor coil sensor | Sensor open/short circuit |
J7 | Failed liquid pipe sensor | Sensor open/short circuit |
J8 | Failed liquid pipe sensor | Sensor open/short circuit |
J9 | Failed sub cool heat exchanger sensor | Sensor open/short circuit |
JA | Failed high pressure sensor | High pressure sensor open/short circuit |
JC | Failed low pressure sensor | Low pressure sensor open/short circuit |
JH | Failed oil temperature sensor | Open/short circuit |
Trouble Shooting
Daikin Fault Codes
Outdoor Fault Codes
Fault Code Definition Supposed Causes Split Skyair VRV Package
L0 | Failure of inverter system | Defect power transistor, inverter PCB |
L1 | Failure of inverter PCB | Blown fuse, defect of inverter PCB, fan motor |
L3 | Electrical box temperature over 120°C when comp’ off | Defect of fan motor, PCB, power transistor |
L4 | Fin temperature over 93°C | Failed sensor, short circuit of airflow |
L5 | Inverter instantaneous DC over current | Defect of inverter PCB, compressor lock/windings |
L6 | Inverter instantaneous AC over current | Defect of inverter unit, compressor lock/windings |
L8 | Over current of inverter compressor | Defect of inverter PCB compressor lock/ windings |
L9 | Inverter compressor start-up failure | Defect of inverter PCB compressor lock/ windings, refrigerant charge |
LA | Failure of power transistor | Defect of power transistor, PCB, compressor |
LC | Communication fails between PCB & micro-computer | Noise, defect of PCB |
LC | Communication fails between main & inverter PCB | Defect of inverter PCB, main PCB, fan PCB, noise filter, compressor |
P1 | Imbalance of power supply | Open phase, imbalance between phases, Defect of main capacitor, inverter PCB |
P2 | Automatic refrigerant charge operation stop | Closed stop valve, closed refrigerant cylinder valve |
P3 | Rise in electrical box temperature | Defect of fin sensor, PCB, rise in ambient temperature |
P4 | Failed radiating fin sensor | Sensor open/short circuit |
P8 | Coil freeze protection during Automatic charging | Close refrigerant cylinder and start again |
P9 | Failure of humidifier fan motor | Defect of fan motor, PCB |
P9 | Automatic charge operation completed | |
PA | Broken humidifier heater wire | Blown thermal fuse, broken heater element |
PA | Refrigerant cylinder empty | Cylinder on master unit empty |
PC | Refrigerant cylinder empty | Cylinder on slave unit empty |
PE | Auto charge nearly completed | |
PH | Humidifier outlet temperature sensor/abnormal heater temp’ | Sensor open/short circuit, defect of PCB, defect of heater unit |
PJ | Capacity not set | Capacity setting adaptor not fitted |
PJ | Capacity setting error | Incorrect capacity setting |
Trouble Shooting
Daikin Fault Codes
System Fault Codes
Fault Code Definition Supposed Causes Split Skyair VRV Package HRV
U0 | Shortage of refrigerant | Undercharged, EEV fault, faulty sensor |
U1 | Reverse or missing phase | Reversed or missing phase |
U2 | Power supply fault | Power supply fault, capacitor wiring error |
U3 | Check operation not executed | Check operation not carried out at commissioning or after main PCB replaced |
U4 | Communication failure, between indoor & outdoor | Wiring fault, defect of PCB, pump wired across communication wiring |
U5 | Communication failure, between r/controller & PCB | Wiring fault, defect of Remote controller & PCB |
U6 | Communication failure between indoor units | Wiring fault, defect of indoor PCB |
U7 | Communication failure, between outdoor PCB’s | Defect of outdoor PCB, wiring error between PCB’s |
U7 Communication failure Wiring error between outdoor units, • • between outdoor units defect of outdoor PCB | ||
U8 Communication failure be- Main/sub switch not set, wiring error, • • • • tween remote controllers defect of remote controller | ||
U9 | System communication failed | Fault with other indoor unit, no power, A9 |
UA | Improper combination | Incorrect field setting, wiring, defect of PCB |
UA | Incorrect field setting Wiring, defective PCB | Field setting incorrect (twin/triple), error in |
UA | Improper combination of Indoor/outdoor units | Excess of indoor units, incorrect PCB Setting, defective PCB |
UC Error in address setting Duplicated central control address • • • • | ||
UE Communication failure Wiring error between indoor unit & central • • • • between indoor central device control, defect of indoor PCB, setting error | ||
UF Wiring/piping mismatch Wiring error indoor to outdoor, PCB defect • • • | ||
UH | System malfunction | Unaddressed indoor unit |
UH | System malfunction | Mismatched indoor/outdoor, freeze protect |
UJ | Communication failure | Defect of accessory device, wiring error |
M1 | Central controller failed | Failure of central controller PCB |
M8 | Communication failure between central & options | Communication failed between central controller & optional controllers |
MA | Improper combination of optional controllers | Incorrect settings, faulty central controller |
MC | Duplicated address | Duplicated central controller address |
60 | Overall alarm | Open circuit across J1-JC |
64 | Failed return air sensor | Sensor open/short circuit |
65 | Failed ambient sensor | Sensor open/short circuit |
6A | Failure of damper system | Defect of damper motor, limit switch, PCB |
Trouble Shooting
common Daikin Air Conditioning Fault Codes
A1 – Micro-computer in PCB is not working – this is a fault that occurs either in the assembly of the PCB or due to an external factor, such as noise.
A3 – Drain level is too high – This is caused by a clogging of dirt in the drain or a faulty drain pump.
A5 – Overheating or freezing of indoor heat exchanger – This could be caused by a dirty air filter, a short circuit or trouble with the sensor in the heat exchange.
A6 – Fan motor error – The fan motor is either locked, overloaded or is suffering from a faulty connection.
A7 – Swing flap motor error – A fault with the swing flap motor, or a faulty connection.
AH – Dust collector error – A fault with the dust collector, or an element of it may be dirty.
AJ – Capacity setting error – The capacity or address set is faulty.
C3 – Abnormal water level sensor resistance – The water level sensor has either disconnected, short-circuited or developed a fault.
C4 – Abnormal resistance level of indoor heat thermistor – This means the thermistor has either become disconnected or it has short-circuited.
C9 – The resistance of the indoor unit suction air thermistor is abnormal – Either a disconnection of the cable or a short circuit has occurred.
CE – Abnormal radiation thermistor resistance – A faulty thermistor, disconnected cable or a short-circuiting of the thermistor could be the source of the issue.
CJ – Abnormal remote controller thermistor resistance – The built-in remote has encountered a fault.
E0 – Outdoor unit protection devices activated – The refrigerant piping system could be clogged, there may be insufficient refrigerant or there could be a fault with the compressor/fan motor.
E3 – High pressure is too high (HPS activation) – The condenser may have short-circuited or overloaded, or the heat exchanger may be dirty.
E4 – Low pressure is too low (LPS activation) – The refrigerant piping system may be clogged, there may be insufficient refrigerant or the LPS switch could be faulty.
E5 – Overheating of compressor (OL activation) – Refrigerant piping system could be clogged, there may not be enough refrigerant, or there could be a fault with the OL or the connection.
F3 – Outdoor unit discharge temperature is too high – Insufficient refrigerant, clogged refrigerant piping or the discharge temperature thermistor could be faulty.
H9 – Abnormal resistance of the outdoor air temperature thermistor – The outdoor air thermistor could be faulty, there may be a cable disconnection or the thermistor itself may have short circuited.
J5 – Abnormal resistance of the suction pipe temperature thermistor – There could be a faulty suction pipe thermistor, the cable could be disconnected or your thermistor may have short circuited.
J6 – Abnormal resistance of the outdoor heat exchanger thermistor – Either a faulty or short-circuited outdoor heat exchanger thermistor or the cable may be disconnected.
P1 – Open-phase power voltage imbalance – This means there’s a three-phase or open-phase voltage imbalance.
U0 – Suction pipe temperature is too high – A fault with the refrigerant piping system – either clogging or a lack of refrigerant or there may be a fault with the expansion valve.
U1 – Reverse phase – The three-phase power supply has been reversed.
U2 – Open phase or power voltage imbalance – There may be an open phase or a voltage imbalance in the power supply. There also could be a power failure or the DC voltage of the fan motor could be too low.
U4 – Communication error between indoor and outdoor units/outdoor and BS units – A mistake with the interconnection wires, or an indoor/outdoor PCB fault.
U5 – Communication error between indoor unit and remote controller – A possible mistake with the interconnection wires, or a PCB fault with the indoor/outdoor remote controller.
UA – Combination error of indoor/BS/outdoor unit, setting error of PCB at the site – There is an incorrect combination of indoor, BS, or outdoor units (the wrong quantity or models, for example).