Daikin AC Error Codes (Troubleshooting Guide)

Daikin Industries Ltd. is a Japanese multinational air conducting company with headquarters in Osaka. Manufacturing a wide range of appliances the company runs operations in Japan, Australia, Chain, India, Europe, the United States, the Middle East, Africa, Latin America, and Southeast Asia. They are the inventors of the VRF (variable refrigerant flow) air conditioner but failed to the trademark, which is why they market their systems as the VRV (variable refrigerant volume).

Founded in 1924, the corporation made headway through the world, taking a slower pace than others. It was not until 2004, that the company entered the North American air conditioning market. From there it took a few years to start offering residential, commercial, and industrial air conditioning units.

To help you out we have listed down some of the most common error codes and troubleshooting for Daikin. Offering consumers a chance to understand the issue at hand before they make a move. We suggest you start by noting down the error code and match it using the list below. Once you have the error code you can easily work your way to the fix, or hire a professional to get it done right the first time around.

Split AC Codes

Error CodesProblem
00Normal
UAIndoor-outdoor Unit Combination Fault
U0Refrigerant Shortage
U2Drop Voltage Or Main Circuit Overvoltage
U4Failure Of Transmission (Between Indoor Unit And Outdoor Unit)
A1Indoor Pcb Defectiveness
A5High Pressure Control Or Freeze-up Protector
A6Fan Motor Fault
C4Faulty Heat Exchanger Temperature Sensor
C9Faulty Suction Air Temperature Sensor
EACooling-heating Switching Error
E1Circuit Board Fault
E5OL Started
E6Faulty Compressor Start Up
E7DC Fan Motor Fault
F3High Temperature Discharge Pipe Control
F6High Pressure Control (In Cooling)
H0Sensor Fault
H6Operation Halt Due To Faulty Position Detection Sensor
H8DC Current Sensor Fault
H9Faulty Suction Air Temperature Sensor
J3Faulty Discharge Pipe Temperature Sensor
J6Faulty Heat Exchanger Temperature Sensor
L3Electrical Parts Heat Fault
L4High Temperature At Inverter Circuit Heatsink
L5Output Overcurrent
P4Faulty Inverter Circuit Heatsink Temperature Sensor

Led On Outdoor Unit PCB

Daikin Led On Outdoor Unit PCB - Flashing
Daikin Led On Outdoor Unit PCB – Flashing

L Series AC Codes

Daikin L-Series Error Codes
Daikin L-Series Error Codes
Error CodesMeaning
00Normal
U0Refrigerant shortage
U2Low-voltage detection or over-voltage detection
U4Signal transmission error (between indoor unit and outdoor unit)
UAUnspecified voltage (between indoor unit and outdoor unit)
A1Indoor unit PCB abnormality
A5Freeze-up protection control or heating peak-cut control
A6Fan motor or related abnormality
C4Indoor heat exchanger thermistor or related abnormality
C9Room temperature thermistor or related abnormality
E1Outdoor unit PCB abnormality
E5OL activation (compressor overload)
E6Compressor lock
E7DC fan lock
E8Input overcurrent detection
EAFourWay valve abnormality
F3Discharge pipe temperature control
F6High pressure control in cooling
H0Compressor system sensor abnormality
H6Position sensor abnormality
H8DC voltage / current sensor abnormality - CT or related abnormality
H9Outdoor temperature thermistor or related abnormality
J3Discharge pipe thermistor or related abnormality
J6Outdoor heat exchanger thermistor or related abnormality
L3Electrical box temperature rise
L4Radiation fin temperature rise
L5Output overcurrent detection
P4Radiation fin thermistor or related abnormality
U7Signal transmission error on outdoor unit PCB
Daikin AC Service Check Function
Daikin AC Service Check Function

Multi-Split Type AC Codes

Daikin Multi-Split Type AC Error Codes
Daikin Multi-Split Type AC Error Codes

Daikin’s multi-split type air conditioning systems offer superior performance, energy-efficiency, and comfort in stylish solutions conforming to all interior spaces and lifestyles. An extensive product lineup utilizes Daikin technology for lower costs and environmental impact. Advanced inverter and heat pump technologies achieve greater efficiency and energy-savings at lower costs. A broad array of models allows the perfect match of style and performance to any interior space.

Error CodesProblem
00Normal
UAIndoor-Outdoor Unit Combination Fault
U0Refrigerant Shortage
U2Drop Voltage or Main Circuit Overvoltage
U4Failure Of Transmission (Between Indoor Unit and Outdoor Unit)
A1Indoor PCB Defectiveness
A5High Pressure Control or Freeze-up Protector
A6Fan Motor Fault
C4Faulty Heat Exchanger Temperature Sensor
C9Faulty Suction Air Temperature Sensor
EACooling-Heating Switching Error
E1Circuit Board Fault
E5OL Started
E6Faulty Compressor Start Up
E7DC Fan Motor Fault
E8Overcurrent Input
F3High Temperature Discharge Pipe Control
F6High Pressure Control (In Cooling)
H0Sensor Fault
H6Operation Halt Due To Faulty Position Detection Sensor
H8DC Current Sensor Fault
H9Faulty Suction Air Temperature Sensor
J3Faulty Discharge Pipe Temperature Sensor
J6Faulty Heat Exchanger Temperature Sensor
L3Electrical Parts Heat Fault
L4High Temperature At Inverter Circuit Heatsink
L5Output Overcurrent
P4Faulty Inverter Circuit Heatsink Temperature Sensor
CTXS, FTXS, CDXS, FDXS, FVXS Series
CTXS, FTXS, CDXS, FDXS, FVXS Series

Daikin VRV IV (4)

Daikin VRV IV Error Codes
Daikin VRV IV Error Codes

The following will be displayed on the screen when an error (or a warning) occurs during operation. Check the error code and take the corrective action specified for the particular model. If unit stops due to an error, the operation indicating LED on the signal receiving part of indoor unit blinks. The error code can be determined by following the procedure described below. (The error code is displayed when an operation error has occurred. In normal condition, the error code of the last problem is displayed.)

Error CodesProblem
A1EEPROM failure (indoor)
A3Drain system malfunction (indoor)
A6Fan motor malfunction (indoor)
A7Swing flap motor malfunction (indoor)
A9Expansion valve malfunction (indoor)
AFDrain malfunction (indoor unit)
AHFilter dust chamber malfunction (indoor)
AJCapacity setting malfunction (indoor)
C1Transmission malfunction between main PCB and sub PCB (indoor)
C4Heat exchanger thermistor malfunction (indoor; liquid)
C5Heat exchanger thermistor malfunction (indoor; gas)
C9Suction air thermistor malfunction (indoor)
CADischarge air thermistor malfunction (indoor)
CEMovement detector or floor temperature sensor malfunction (indoor)
CJUser interface thermistor malfunction (indoor)
E1PCB malfunction (outdoor)
E2Current leakage detector was activated (outdoor)
E3High pressure switch was activated
E4Low pressure malfunction (outdoor)
E5Compressor lock detection (outdoor)
E7Fan motor malfunction (outdoor)
E9Electronic expansion valve malfunction (outdoor)
F3Discharge temperature malfunction (outdoor)
F4Abnormal suction temperature (outdoor)
F6Refrigerant overcharge detection
H3High pressure switch malfunction
H4Low pressure switch malfunction
H7 Fan motor trouble (outdoor)
H9 Ambient temperature sensor malfunction (outdoor)
J1Pressure sensor malfunction
J2Current sensor malfunction
J3Discharge temperature sensor malfunction (outdoor)
J4Heat exchanger gas temperature sensor malfunction (outdoor)
J5Suction temperature sensor malfunction (outdoor)
J6De-icing temperature sensor malfunction (outdoor)
J7Liquid temperature sensor (after subcool HE) malfunction (outdoor)
J8 Liquid temperature sensor (coil) malfunction (outdoor)
J9 Gas temperature sensor (after subcool HE) malfunction (outdoor)
JA High pressure sensor malfunction (S1NPH)
JCLow pressure sensor malfunction (S1NPL)
L1 INV PCB abnormal
L4Fin temperature abnormal
L5 Inverter PCB faulty
L8Compressor over current detected
L9 Compressor lock (startup)
LC Transmission outdoor unit - inverter: INV transmission trouble
P1 INV unbalanced power supply voltage
P2Autocharge operation related
P4Fin thermistor malfunction
P8Autocharge operation related
P9 Autocharge operation related
PEAutocharge operation related
PJ Capacity setting malfunction (outdoor)
U0 Abnormal low pressure drop, faulty expansion valve
U1Reversed power supply phase malfunction
U2INV voltage power shortage
U3System test run not yet executed
U4 Faulty wiring indoor/outdoor
U5Abnormal user interface - indoor communication
U7Faulty wiring to Q1/Q2
U8Abnormal main-sub user interface communication
U9System mismatch. Wrong type of indoor units combined. Indoor unit malfunction
UA Connection malfunction over indoor units or type mismatch
UCCentralized address duplication
UEMalfunction in communication centralized control device - indoor unit
UFAuto address malfunction (inconsistency)
UH Auto address malfunction (inconsistency)

Daikin VRV III (3)

Daikin VRV III 3 Error Codes
Daikin VRV III 3 Error Codes

If operation stops due to malfunction, the remote control operation LED blinks, and malfunction code is displayed. (Even if stop operation is carried out, malfunction contents are displayed when the inspection mode is entered.)

1. Pressing the INSPECTION/TEST button will blink the check indication.

2. While in check mode, pressing and holding the ON/OFF button for a period of five seconds or more will clear the failure history indication shown above.

Error CodesProblem
A0Error of external protection device
A1PC board defect, E2 PROM defect
A3Malfunction of drain level control system (S1L)
A6Fan motor (M1F) lock, overload
A7Malfunction of swing flap motor (M1S)
A9Malfunction of moving part of electronic expansion valve (Y1E)
AFDrain level above limit
AJ Malfunction of capacity setting
C4Malfunction of thermistor (R2T) for heat exchange
C5Malfunction of thermistor (R3T) for gas pipes
C9 Malfunction of thermistor (R1T) for air inlet
CAMalfunction of thermistor for air inlet
CJ898 Malfunction of thermostat sensor in remote control
E1PC board defect
E3 Actuation of high pressure switch
E4Actuation of low pressure sensor
E5Compressor motor lock
E6Standard compressor lock or over current
E7Malfunction of outdoor unit fan motor
E9Malfunction of moving part of electronic expansion valve (Y1E, Y2E)
F3Abnormal discharge pipe temperature
F6Refrigerant overcharged
H3Failure of high pressure switch
H4Actuation of low pressure switch
H7 Abnormal outdoor fan motor signal
H9Malfunction of thermistor (R1T) for outdoor air
J2Current sensor malfunction
J3 Malfunction of discharge pipe thermistor
J5 Malfunction of thermistor (R3T, R5T) for suction pipe
J6Malfunction of thermistor (R6T) for heat exchanger
J7Malfunction of receiver outlet liquid pipe thermistor (R7T)
J9Malfunction of subcooling heat exchanger gas pipe thermistor
JAMalfunction of discharge pipe pressure sensor
JCMalfunction of suction pipe pressure sensor
L0Inverter system error
L1 Malfunction of PC board
L4 Malfunction of inverter radiating fin temperature rise
L5 DC output overcurrent of inverter compressor
L8Inverter current abnormal
L9Inverter start up error
LAMalfunction of power unit
LCMalfunction of transmission between inverter and control PC board
P1 High voltage of capacitor in main inverter circuit
U0Low pressure drop due to refrigerant shortage or electronic expansion valve failure
U1Reverse phase / open phase
U2Power supply insufficient or instantaneous failure
U3Check operation is not completed
U4Malfunction of transmission between indoor and outdoor units
U5Malfunction of transmission between remote control and indoor unit
U6 Failure of remote control PC board or setting during control by remote control
U7 Malfunction of transmission between outdoor units
U8Malfunction of transmission between main and sub remote controls
U9 Malfunction of transmission between indoor unit and outdoor unit in the same system
UA Improper combination of indoor and outdoor units,indoor units and remote control
UCAddress duplication of central remote control
UE Malfunction of transmission between central remote control and indoor unit
UFRefrigerant system not set, incompatible wiring /piping
UHMalfunction of system, refrigerant system address undefined
UE Malfunction of transmission between central remote control and indoor unit
M1Central remote control PC board defect Schedule timer PC board defect
M8Malfunction of transmission between optional controllers for centralized control
MAImproper combination of optional controllers for centralized control
MCAddress duplication, improper setting
64 Indoor unitís air thermistor error
65 Outside air thermistor error
68Malfunction of HVU
6ADamper system alarm
6A Damper system + thermistor error
6FMalfunction of simple remote control
94Internal transmission error

Troubleshooting

Daikin AC Troubleshooting
Daikin AC Troubleshooting

The following incidents do not indicate a malfunctioning air conditioner and have explanations. The air conditioner can continue to operate.

Case: The outdoor unit emits water or steam.

Explanation:

  • In HEAT operation; The frost on the outdoor unit melts into water or steam when the air conditioner is in defrost operation.
  • In COOL or DRY operation; Moisture in the air condenses into water on the cool surface of outdoor unit piping and drips.

Case: Mist comes out of the indoor unit.

Explanation:

  • This happens when the air in the room is cooled into mist by the cold airflow during COOL operation.
  • This is because the air in the room is cooled by the heat exchanger and becomes mist during defrost operation.

Case: The indoor unit gives out odor

Explanation:

  • This happens when smells of the room, furniture, or cigarettes are absorbed into the unit and discharged with the airflow. If this happens, it is recommended to have the indoor unit washed by a technician. Consult the service shop where you purchased the air conditioner.

Case: The outdoor fan rotates while the air conditioner is not in operation.

Explanation:

  • After operation is stopped; The outdoor fan continues rotating for another 60 seconds for system protection.
  • While the air conditioner is not in operation; When the outdoor temperature is very high, the outdoor fan starts rotating for system protection.

Case: Possible sounds.

Explanation:

  • Flowing water; Generated because the refrigerant in the air conditioner is flowing. This is a pumping sound of the water in the air conditioner and heard when the water is pumped out from the air conditioner in cooling or drying operation. The refrigerant flows in the air conditioner even if the air conditioner is not working when the indoor units in other rooms are in operation.
  • Blowing; Generated when the flow of the refrigerant in the air conditioner is switched over
  • Pinging; Generated when the size of the air conditioner slightly expands or shrinks as a result of temperature changes.

Case:The air conditioner does not operate

Check:

  • Is a breaker off or a fuse blown?
  • Is there a power failure?
  • Are batteries set in the remote controller?
  • Is the timer setting correct?

Case: Cooling (Heating) effect is poor

Check:

  • Are the air filters clean?
  • Is there anything to block the air inlet or the outlet of the indoor and the outdoor units?
  • Is the temperature setting appropriate?
  • Are the windows and doors closed?
  • Are the airflow rate and the airflow direction set appropriately?

Case: Operation stopped suddenly

Check:

  • Are the air filters clean?
  • Is there anything to block the air inlet or the outlet of the indoor and the outdoor units?
  • Clean the air filters or take all obstacles away and turn the breaker off. Then turn it on again and try operating the air conditioner with the remote controller. If the lamp still flashes, call the service shop where you purchased the air conditioner.
  • Are operation modes all the same for indoor units connected to outdoor units in the multi system?

Manuals PDF

VRV 3 Service Manual

Split AC Manual

L-Series AC Manual

VRV IV Service Manual

Simple Self-Diagnosis by Malfunction Code

References

daikin.com

daikin.com.au

daikinac.com/content/assets/DOC/ServiceManuals

ft.com/content/a677c087-ef43-4100-9705-27e131846625



*If you can't find the code you're looking for on our site, please let us know, and we'll update our database as soon as possible.

26 thoughts on “Daikin AC Error Codes (Troubleshooting Guide)”

  1. In the afternoon, I want to ask about the problem with the split duct ac model RNQ30MY14, if it operates, there is an error, then we use the operation with an emergency system?

    Reply
  2. I get error code U4. I have done all the recommended fixes, even crawled under the house to check the wiring…all good. I replaced the fuses, checked the wire configuration and connections, all good. It has worked for the last 2 years with no issues, now this. could it be a faulty control board in the outdoor unit? I got it to work this weekend and it stopped again today with the same u4 code.
    Unit is the Daikin FTX24NMVJU any help would be greatly appreciated.

    Reply

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