Daikin air conditioner fault codes, meaning, and fixes

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This Daikin air conditioner fault codes list will help you repair your AC..

Like other appliances, your Daikin air conditioner will occasionally malfunction due to defects in some parts of the air con or even issues such as incorrect installation or wrong settings.

The good thing is these units are pre-programmed and will display relevant error codes on the control panel so a great place to start your troubleshooting is checking the error code it is showing then fixing it appropriately.

Below is a list of typical Daikin air conditioner fault codes and their meaning. The guide also includes potential solutions for some of the errors to help you get the AC running again.

Table of Contents

Daikin air conditioner fault codes (what they mean, how to fix each and how to reset Daikin air conditioner fault codes)

These are the most common Daikin air conditioner fault codes and the recommended Daikin air conditioner troubleshooting for selected issues:

List of Daikin air conditioner fault codes, meaning, causes and  repair steps for Daikin RA, SkyAir, VRV  multi-split air conditioner, etc.

Indoor unit Daikin air conditioner fault codes

Error A0- External protection device activated

Probable causes:

  • External protection device is connected to terminal strip.
  • T1-T2 of the indoor unit has activated.

Error A1- Malfunction of Daikin PCB on indoor unit

Probable causes:

  • Defective PCB in indoor unit.
  • External factor such as Noise etc.

Error A3- Drain Level Control System Abnormality

Probable causes:

  • Upward slope, drain clogging, etc.
  • Faulty drain pump.
  • Defective float switch/short circuit connector

Error A4- freezing protection malfunction

Probable causes:

  • Water volume shortage
  • Low water temp. setting
  • Water temperature thermistor not functional.

Daikin A5 error- High pressure control in heating, freeze-up protection control in cooling

Probable causes:

  • Clogged air filter (of indoor unit) and short circuit
  • Defective indoor unit’s heat exchanger thermistor

How to fix A5 error Daikin

Check that the indoor/outdoor heat exchanger is not clogged. In addition, check the filters.

To reset, turn off power to the AC system for approx.. 5 minutes then retry.

Error A6- fan motor malfunction

Probable causes:

  • Broken wiring in or short circuit of or the disconnection of connector(s) from fan motor harness
  • Faulty fan motor.
  • Issue in indoor unit’s PCB

How to fix Daikin error code A6

  1. Repair the wiring.
  2. Test the fan -put your indoor unit in “fan only” and try to run the fan in different speeds. Is it working correctly? If yes, test the fan motor.

How to test fan motor

Start by checking the power supply to the motor- simply unhook your fan lead from PCB and check for the correct voltage (from the board).
If it turns out that the PCB is supplying power as expected but the fan motor is still not starting at all, proceed to replace the motor.
But If the PCB won’t provide power, get a replacement PCB (but be sure to check the fuses on the PCB as they could be causing the issue).

Error A7- swing flap motor malfunction

Probable causes:

  • Swing flap motor is itself defective.
  • Indoor unit PCB defective.
  • Connection cable defective.
  • The air flow direction adjusting flap-cam is faulty.

Error A8- Malfunction of power supply or AC input overcurrent

Probable causes:

  • Power supply voltage is defective
  • Connection on the signal line is faulty.
  • Bad wiring.

Error A9- electronic expansion valve malfunction

Probable causes:

  • Faulty electronic expansion valve coil.
  • Malfunction in indoor unit PCB.
  • Defective relay cables.

Error AA- Heater overheat

Probable causes:

  • 26WH is activated

Error AF- humidifier system malfunction

Probable causes:

  • Humidifier unit is leaking (where applicable).
  • Faulty drain piping (up-ward slope, etc.)
  • Damaged indoor unit PCB.

Error AH- Malfunction of dust collector of air cleaner

Probable causes:

  • Dust collecting element not working.
  • Stained insulator part.
  • High-voltage power supply unit defective.
  • Indoor unit PCB defective.

Error AJ- Capacity setting malfunction (Indoor unit PCB)

Probable causes:

  • The installation of Daikin capacity setting adaptor was not done when replacing the PCB.
  • Indoor unit PCB defective.

Error C1- transmission between indoor unit PCB and sub PCB failed.

Probable causes:

  • Faulty connection of connector between the indoor unit PCB.

Error C4- liquid pipe thermistor (for heat exchanger) malfunction

Probable causes:

  • Thermistor for liquid pipe defective.
  • Indoor unit PCB defective.
  • Defective connector contact

Error C5- gas pipe thermistor (for heat exchanger) malfunction

Probable causes:

  • Thermistor for gas pipe defective.
  • Indoor unit PCB defective.
  • Defective connector contact

Error C6- fan motor sensor/fan control driver malfunction

Probable causes:

  • Defective fan PCB
  • Field setting error
  • Defective connection of the capacity setting adaptor

Error C7- fault in front panel driving motor

Probable causes:

  • Front panel driving motor has failed.
  • Faulty limit switch

Error C9- suction air thermistor malfunction

Probable causes:

  • Thermistor for suction air defective
  • Indoor unit PCB defective
  • Faulty connector contact

Error CA- discharge air thermistor malfunction

Probable causes:

  • Thermistor for discharge air defective
  • Indoor unit PCB defective
  • Faulty connector contact

Error CC- humidity sensor system malfunction

Probable causes:

  • Faulty humidity sensor
  • Defective connector contact

 

Error CJ- abnormality in the room temperature thermistor (in remote controller)

Probable causes:

  • Room temperature thermistor (in remote controller) faulty.
  • Remote controller PCB defective.
  • External factors (Noise etc.)

 

Outdoor unit Daikin air conditioner fault codes

Error E0-Protection devices activated (unified)

Probable causes:

  • Protection device connected to out door unit PCB actuated
  • Protection device connector contact defective

Error E1-Defective outdoor unit PCB

Probable causes:

Either the outdoor unit PCB is defective or the connection of the inside/outside relay wires is defective.

How to fix error E1

Repair the connection of the inside/outside relay wires or replace the outdoor PCB if found faulty.

Error E2- Missing of earth leakage detection core

This code is displayed when PCB detects a current leakage. (The code will be generated once related defects are detected, for example, compressor insulation failure.

Error E3- high pressure switch (HPS) actuation

Probable causes:

  • Dirty heat exchanger (outdoor unit)
  • High pressure switch is defective.
  • Clogged refrigerant piping.
  • Faulty connector contact.

Error E4- low pressure switch (LPS) actuation

Probable causes:

  • Abnormal drop in low pressure
  • Faulty low pressure sensor
  • Nonfunctional outdoor unit PCB
  • Defective connector contact

Error E5- Inverter compressor motor overheat

Probable causes:

  • High differential pressure
  • Inverter compressor lock
  • UVW connection error
  • Defective inverter PCB
  • Defective connector contact

Error E6-STD compressor motor overcurrent/lock

Probable causes:

  • Defective control PCB
  • Defective compressor
  • Stop valve not opened

Daikin Error code E7 (daikin air conditioner error code e7) – outdoor unit fan motor system malfunction

Probable causes:

  • Fan motor has failed.
  • Neglect to connect/defective connection of the harness/connector between fan motor and PCB
  • Fan fails to rotate due to some foreign matters stuck in it

Error E8- inverter compressor overcurrent

Probable causes:

  • Defective main circuit capacitor in inverter.
  • Failed compressor
  • Defective outdoor unit PCB
  • Defective power transistor

Error E9- electronic expansion valve coil malfunction

Probable causes:

  • Connectors are disconnected from the electronic expansion valves
  • Electronic expansion valve coil issues
  • Faulty outdoor unit’s control PCB

Error EA- four way valve or cool/heat switching malfunction

Probable causes:

  • Faulty four way valve
  • Gas shortage.
  • Faulty outdoor unit’s control PCB
  • Defective thermistor

Error EC- entering water temperature malfunction

Probable causes:

  • Cooling water temp abnormality
  • Faulty outdoor unit’s control PCB
  • Defective thermistor

Daikin error code F3 – discharge pipe temperature malfunction

Probable causes:

  • Discharge pipe thermistor defective
  • Abnormal discharge pipe temp.
  • Faulty outdoor unit’s control PCB
  • Defective connector contact

Error F6- Abnormal high pressure/refrigerant overcharged

Probable causes:

  • Refrigerant overcharged
  • Outdoor air thermistor disconnected.
  • Heat exchanger deicer thermistor disconnected.
  • Liquid pipe temperature thermistor disconnected.
  • Faulty outdoor unit’s PCB

Error H0- compressor sensor system malfunction

Probable causes:

  • Harness is disconnected (or not properly connected)
  • Defective PCB

Error H1- room temperature sensor/humidifier unit damper malfunction

Probable causes:

  • Defective damper
  • Defective limit switch

Error H3- high pressure switch (HPS) malfunction

Probable causes:

  • High pressure switch defective
  • Broken wire
  • Outdoor unit PCB defective
  • Connector contact defective

Error H4- Low pressure switch (LPS) malfunction

Probable causes:

  • Faulty low pressure switch
  • Broken wire
  • Outdoor unit PCB defective
  • Connector contact defective

Error H5- compressor motor overload thermistor malfunction

Probable causes:

  • Compressor motor over-load thermistor defect.
  • Defective connector contact

How to fix Error H5

  • Repair the connector contact
  • Check the overload thermistor first and replace if necessary.

Error H6- position detection sensor malfunction

Probable causes:

  • Faulty contact of compress/cable
  • Defective compressor
  • Faulty outdoor unit PCB

Error H7- outdoor unit fan motor signal malfunction

Probable causes:

  • Abnormal signal from the fan motor (Circuit failure)
  • Disconnection/Short circuiting in fan motor lead(s) or the connector has disconnected.
  • Faulty inverter PCB

Error H8- compressor input (CT) system malfunction

Probable causes:

  • Defective reactor
  • Defective power transistor
  • Faulty wiring of the inverter system
  • Faulty outdoor unit PCB

Error H9- outdoor air thermistor malfunction

Probable causes:

  • Connection of thermistor defective
  • Faulty outdoor unit PCB
  • Outdoor air thermistor is defective.
  • Faulty suction air temperature sensor Daikin

Error HC- (hot) water temperature thermistor malfunction

Probable causes:

  • Connection of thermistor is defective.
  • Outdoor unit PCB defective.
  • Water temperature thermistor defective.

 

Error HF- Alarm in thermal storage unit or storage controller

Probable causes:

  • Defective wiring in thermal storage group.
  • Defective settings
  • Excess thermal storage tank numbers.

Error HJ- thermal storage tank water level malfunction

Probable causes:

  • Low water level
  • Wrong switch setting
  • Water levels detecting sensor failure
  • Defective connector contact

Error J1- pressure sensor malfunction

Probable causes:

  • Faulty pressure sensor connector contact
  • Pressure sensor defective.
  • Outdoor unit PCB defective.

Error J2- compressor current sensor malfunction

Probable causes:

  • Defective compressor
  • Defective current sensor
  • Outdoor unit PCB defective.

Error J3- discharge pipe thermistor malfunction

Probable causes:

  • Connection of thermistor defective.
  • Discharge pipe thermistor defective.
  • Outdoor unit PCB defective.

Error J4- low pressure equivalent saturated temperature sensor system malfunction

Probable causes:

  • Connection of thermistor defective.
  • Defective thermistor
  • Outdoor unit PCB defective.

Error J5- suction pipe thermistor malfunction

Probable causes:

  • Connection of thermistor defective.
  • Suction pipe thermistor defective.
  • Outdoor unit PCB defective.

Error J6- heat exchanger thermistor malfunction

Probable causes:

  • Connection of thermistor defective.
  • Heat exchanger thermistor defective.
  • Outdoor unit PCB defective.

Error J7- thermistor (Refrigerant circuit) malfunction

Probable causes:

  • Connection of thermistor defective.
  • Liquid pipe thermistor defective.
  • Outdoor unit PCB defective.

Error J8- thermistor (Refrigerant circuit) malfunction

Probable causes:

  • Connection of thermistor defective.
  • Liquid pipe thermistor defective.
  • Outdoor unit PCB defective.

Error J9- thermistor (Refrigerant circuit) malfunction

Probable causes:

  • Connection of thermistor defective.
  • Gas pipe thermistor defective.
  • Outdoor unit PCB defective.

Error JA- high pressure sensor malfunction

Probable causes:

  • Defective connector contact
  • Low pressure sensor connection is in mistake for high pressure sensor
  • High pressure sensor defective.
  • Outdoor unit PCB defective.

Error JC- low pressure sensor malfunction

Probable causes:

  • Defective connector contact
  • High pressure sensor connection is in mistake for low pressure sensor
  • Low pressure sensor defective.
  • Outdoor unit PCB defective.

Error JE- oil pressure sensor/sub-tank thermistor malfunction

Probable causes:

  • Defective connector contact
  • Defective sub-tank thermistor
  • Outdoor unit PCB defective.

Error JF- oil level sensor/heating heat exchanger thermistor malfunction

Probable causes:

  • Defective connector contact
  • Heat exchanger thermistor defective.
  • Outdoor unit PCB defective.

Error L0- inverter system malfunction

Probable causes:

  • Power supply capacity shortage.
  • Defective power transistor
  • Outdoor unit PCB defective

Error L1- inverter PCB malfunction

Probable causes:

  • Compressor wiring faulty.
  • Defective outdoor unit’s fan motor
  • Blown fuse
  • Faulty inverter PCB

Error L3- El.Compo. Box temperature rise

Probable causes:

  • Fin temperature rise because of short circuit
  • Defective outdoor unit’s fan motor
  • Defective power transistor
  • Outdoor unit PCB defective

Error L4- inverter radiation fin temperature rise malfunction

Probable causes:

  • Fin temperature rise as a result of short circuit
  • Defective fin thermistor

Daikin error code L5 – Inverter instantaneous overcurrent (DC output)

Probable causes:

  • Defective compressor coil (like wiring disconnection/insulation failure)
  • Compressor start-up failure (mechanical lock)
  • Inverter PCB defective

Troubleshooting steps

Check that the compressed hasn’t seized. You can use the Megger tester. Also check if the inverter board is in good condition with inverter checker

Error L6- Inverter instantaneous overcurrent (AC output)

Probable causes:

  • Refrigerant amount overcharge.
  • Power supply capacity shortage.
  • Defective compressor
  • Faulty inverter unit

Error L8- overcurrent inverter compressor malfunction

Probable causes:

  • Compressor over-loaded
  • Wiring disconnection in the compressor coil
  • Disconnection of the compressor wiring
  • Faulty inverter PCB

Error L9- inverter compressor start-up error (Stall prevention) malfunction

Probable causes:

  • Stop valve not opened
  • Defective compressor
  • Error in wiring connections to compressor
  • Large differential pressure prior to compressor startup
  • Defective inverter PCB

Error LA- power transistor malfunction

Probable causes:

  • Defective compressor
  • Defective power transistor
  • Defective inverter PCB

Error LC- transmission between control and inverter PCB malfunction

Probable causes:

  • Defective connection between inverter PCB and control PCB
  • External factors (such as noise)
  • Faulty inverter compressor
  • Faulty control PCB (transmission block)

Error P0- insufficient refrigerant amount(thermal storage unit)

Probable causes:

  • Shortage of refrigerant.
  • Clogged refrigerant piping.

Error P1- Power voltage imbalance/inverter PCB problem

Probable causes:

  • Open phase
  • Interphase voltage imbalance
  • Defective capacitor (in the main circuit)
  • Defective wiring (in the main circuit)
  • Faulty inverter PCB

Error P2- Automatic refrigerant charge operation stopped

Probable causes:

  • Stop valve not opened
  • Closed refrigerant tank valve.

Error P3- thermistor in switch box fault

Probable causes:

  • Defective connection of the thermistor
  • Faulty reactor thermistor
  • Defective inverter PCB

Error P4- radiation fin temperature sensor has malfunctioned

Probable causes:

  • Faulty radiation fin temperature thermistor
  • Defective inverter PCB
  • Faulty INV. compressor
  • Faulty fan motor

Error P8- Heat exchanger freezing protection during automatic refrigerant charging

You should close the refrigerant cylinder then start again from the first step.

Error P9- fan motor (humidifier unit) malfunction

Probable causes:

  • Defective fan motor
  • Outdoor unit PCB defective
  • Broken relay harness
  • Defective connector contact

Error PA- Broken wire of heater(humidifier unit)

Probable causes:

  • Faulty heater unit
  • Defective thermistor
  • Faulty outdoor unit PCB

Error PJ- Improper combination between inverter and fan driver OR for Skyair models Malfunction of the capacity setting (Outdoor unit PCB)

Probable causes:

  • Mis-matching of the type of PCB
  • Improper (or no) field setting after you have replaced outdoor unit’s main PCB

OR (for Skyair PJ error)

  • Capacity setting adaptor not installed
  • Incorrect capacity setting adaptor
  • Faulty outdoor unit PCB

 

System error codes

Daikin Error code u0- Shortage of refrigerant

Probable causes:

  • Refrigerant shortage and/or refrigerant clogging (wrong piping)
  • Defective Daikin thermistor
  • Defective low-pressure sensor
  • Defective outdoor unit’s main PCB

Error U1- Reverse phase, open phase

Probable causes:

  • Power supply reverse phase
  • T- phase open phase
  • Faulty outdoor unit PCB (A1P)

Daikin Error code  U2- power supply malfunction or instantaneous power failure

Probable causes:

  • Abnormal/irregular power supply voltage
  • Instantaneous power failure
  • Faulty main circuit wiring

Error U3- Check operation not executed/transmission error

Probable causes:

The check operation was not executed

Daikin u4 error code – transmission between indoor and outdoor unit malfunction

Probable causes:

  • Short circuit in indoor-outdoor/outdoor-outdoor
  • Transmission wiring issue (F1/F2) or wrong wiring
  • Outdoor unit’s power supply OFF
  • System address not matching
  • Faulty indoor unit PCB
  • Outdoor unit PCB defective

Daikin U4 error fix (how to fix Daikin error code U4)

The best way to deal with the Daikin air conditioner error code u4 is to do a hard reset.

Here is how to reset Daikin error codes U4:

Simply try to hard reset the unit for 30 seconds then turn off the outdoor unit (the steps may differ for your model so refer to your manual for correct hard resetting procedure).

Error U5- transmission between indoor unit and remote controller malfunction

Probable causes:

  • Transmission error between the indoor unit and the remote controller.
  • Connection of the 2 main remote controllers (when using two remote controllers) problematic.
  • Faulty indoor unit PCB
  • Faulty remote controller PCB
  • Transmission error due to noise

Error U6- transmission between indoor units malfunctioned

Probable causes:

  • Faulty wiring
  • External factors (Noise etc.)
  • Faulty indoor unit PCB

Error U7- transmission between outdoor units or outdoor storage unit malfunction

Probable causes:

  • Connection error of the transmission wirings between the outdoor unit and the external control adaptor (for the outdoor unit)
  • Connection error of the transmission wirings between the outdoor units
  • Outdoor unit PCB defective

Error U8- transmission between remote controllers malfunctioned

Probable causes:

  • Transmission error between the main & sub remote controller
  • Connection between the sub remote controllers has issues
  • Remote controller PCB is defective.

Error U9- Malfunction of transmission (other system)

Probable causes:

  • Transmission error between the other indoor & outdoor units
  • Electronic expansion valve (of other indoor unit) is defective.
  • Indoor unit PCB (of other indoor unit) is defective.
  • Improper connection of the transmission wiring between the indoor & outdoor unit

Error UA- Improper combination of indoor and outdoor units or Defect of indoor/outdoor power supply

Probable causes:

  • Excess of the connected indoor units
  • Outdoor unit PCB defective
  • Mismatch of refrigerant type of the indoor and outdoor unit
  • Setting of the outdoor unit PCB was not done after replacing to spare PCB

OR

  • Improper power supply
  • Wrong model connections
  • Wrong PCB connected
  • Defective PCB

Error UC- Malfunction of setting of centralized control equipment address

Probable causes:

  • Centralized control equipment address duplicated
  • Indoor unit PCB defective.

Error UE- Malfunction of transmission between indoor unit and centralized control equipment

Probable causes:

  • Transmission error between the optional controllers for the centralized control equipment and the indoor unit
  • Connector for setting the main controller is not connected (or a disconnection of the connector for independent/combined use changeover switch has occurred)
  • Defective PCB (for central remote controller)
  • Indoor unit PCB defective

Probable causes:

  • Improper connection of the transmission wiring between indoor-outdoor units & outdoor-outdoor units
  • Failure to perform check operation
  • Indoor unit PCB is defective.
  • Stop valve not opened

Error UH- Malfunction of system

Probable causes:

  • Improper connection of the transmission wiring between indoor-outdoor units and the outdoor-outdoor units.
  • Indoor unit PCB defective.
  • Outdoor unit PCB defective.

Error UJ- Malfunction of transmission (accessory device)

Probable causes:

  • Defect of the accessory devices
  • Faulty wiring

Error M1- Malfunction of central remote controller PCB

Probable causes:

  • Faulty central remote controller PCB

Error M8- Malfunction of transmission between optional controllers for centralized control

Probable causes:

  • Other centralized control power disconnected
  • Centralized control re-set switch ON
  • Faulty transmission wiring
  • Change in central remote controller’s address

Error MA- Improper combination of optional controllers for centralized control

Probable causes:

  • Improper combination of the optional controllers , of course, for centralized control
  • More than one(1) master controller has been connected
  • Faulty settings of centralized control
  • Defective centralized control

Error MC- Address duplication, improper setting

Probable causes:

  • Address duplication of the central remote controller

Other Daikin air conditioner fault codes and their meaning

Daikin error code 00

This is not an actual issue- it indicates that your AC is running normally!

Daikin error code blinking / Daikin air conditioner light blinking

This communicates that there is an issue with your system. You can clear it by pressing then holding the “Cancel” button for about 5 seconds.

Error C0- sensor system (unified) malfunction

For this error code, try to clean the condense tray and the pump thoroughly.

 

Daikin air conditioner fault codes – useful tips when diagnosing Daikin vrv error codes

Make use of the Daikin troubleshooting app (Daikin Service Application)

Another self-diagnosis approach you can take is looking up your air conditioner error codes in the Daikin Service Application.

The app support Daikin Equipment service engineers and you can get help and useful pointers by simply following the steps below:

How to check Daikin error code in the app

Simply type the Daikin air conditioner fault codes you have noticed in the search window and voila! you get answers to the fault codes bothering you.

Download the app here if you are yet to do so.

Alternative Method -how to check Daikin error code with remote

1) Open the cover (the remote control cover)
(2) Press CANCEL button for about 5 seconds while pointing the remote control at your indoor unit. The screen/display on your remote controller will now show an error code (and beep)
how to check daikin error code with remote

Alternative method 2 -how to check Daikin error code on remote

(1) Open the remove control cover.
(2) Press SET UP button (on the remote) for 5 seconds.
(3) Press the up (^) or down(v) button and then select/choose Checking error code
(4) Press APPLY button while pointing the remote control at your indoor unit. The display(on the remote control) should now show a fault code and you’ll hear a long beep(at the same time).
Quick Tip: To return to normal mode(on the remote), press SET UP button for about 5 seconds once again or leave your remote
control untouched for around 60 seconds.
how to check daikin error code on remote

Daikin hard reset – How to reset Daikin error codes

There are times your unit won’t work no matter what you try.

In such situations, the best approach is performing a hard reset on your AC system.

Here is how to reset Daikin error codes in most models:

  1. On your Daikin remote control, locate the On/Off button.
  2. Now press this On/Off button and proceed to hold it for about 2 seconds before releasing it.
  3. Next press the On/Off switch (once) – this stops operations.
  4. Finally, press the On/Off switch a second time- this restarts the unit.

Daikin thermostat reset (Daikin ENVi thermostat)

Your Daikin ENVi thermostat comes with a nice, easy-to-read screen that displays all the important information you may need to set/manage the thermostat.

Now, at some point, you may need  to quickly reconfigure your Daikin thermostat or restore the accessory to its default state.

If this is what you want to do, these are your options:

  • Reset Registration – choose this to Reset the connection between your Daikin thermostat and personalized Web Portal.
  • Preferences and Schedule– select this to Reset all preferences, alerts, reminders, and programming back to defaults.
  • HVAC Equipment Settings– use this to Reset the configuration of your Indoor Unit and/or the auxiliary heat equipment.
  • All Settings– This is the option to select when you want to Reset the Daikin thermostat itself back to the default factory settings.

Now, to perform a reset for your Daikin thermostat:

  1. From the ‘Home’ screen, press MENU
  2. Next, Select Settings
  3. Then select Reset.
  4. Select the reset option according to your needs.

To Reboot the Daikin Thermostat:

  1. Press the physical hardware re-set button- it located through the opening (in the bottom-left corner) of your Daikin ENVi thermostat.

Note that rebooting does not alter programming/configuration options.

Daikin thermostat troubleshooting

Your Daikin thermostat can produce these alert messages. Bear in mind that depending on your settings, some may not apply.

  • Low Temp Limit-Temperature in your home is extremely low.
  • High Temp Limit– Temperature in your home is extremely high.
  • Heat Not Responding– The system has been unable to heat your home.
  • Cool Not Responding– The system is failing to cool your home.
  • System Service– your HVAC system is due for its regular maintenance.
  • Auxiliary Heat RunTime– auxiliary heat source running too often.
  • Auxiliary Outdoor Temperature– Your auxiliary heat is being made to run when outdoor temperature exceeds programmed set point.
  • System error (service required)- A system malfunction occurred. To reset the error status, select Settings then Installation Settings then Force System Off. This turns off your blinking LED.
  • Lost communication– Communication with your Indoor Unit lost. Check all the wiring connections- between the DPCA, thermostat, and the Indoor Unit.

Further thermostat related troubleshooting

When controlling residential heat pump system (and calling for cooling), heat comes on.

Possible cause: Reversing valve jumper on the thermostat has been set for “B”.

Potential solution: The said reversing valve jumper should be set for “O”.

When asking for cooling, both heat and cool comes on.

Possible cause: Thermostat equipment jumper configured for “HP” and HVAC system is Electric/Gas.

Potential solution: The equipment jumper to be set for “Gas”.

When you press the Program button, the display shows “DISABLED”.

Possible cause: Program mode has been set to “NONPROGRAM”.

Potential solution: Set Program Mode to 1, 5/2, or 7-Day

 

Daikin air conditioner fault codes and how to fix them – Helpful video

Wrap up

Most Daikin air conditioners come pre-programmed with various error codes to help you repair faults when the unit fails.

Use the above Daikin error codes list to clear the fault and keep the heat wave at bay.

And oh, don’t forget to consult your Daikin air conditioner manual – it usually has a section listing everyday error codes and applicable troubleshooting steps.

Of course, it’s best to involve a pro or Daikin tech support if you come across a strange error code or if your Daikin AC problem still remains even after trying the various repair instructions.

ALSO READ:

Daikin thermostat reset – step by step instructions

How to reset Daikin Air Conditioner [Steps]

Daikin air conditioner flashing green light U4 [Fixed]

Daikin air conditioner not turning on [Fixed!]

AC power consumption vs temperature

York air conditioner problems and troubleshooting guide

Here is why your Portable air conditioner fills with water quickly

Chigo air conditioner problems and solutions (comprehensive guide)

Arctic king air conditioner troubleshooting guide and tips

 

 

1 thought on “Daikin air conditioner fault codes, meaning, and fixes”

  1. This would be good if I could find the specific error code and history.
    All that my thermostat says is “Fan Failure Error.” This does not tell me what the code is or where to find the code.

    Reply

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