Daikin Error Codes (Malfunction Self-diagnosis and Troubleshooting) - CoolAutomation (2024)

Indoor UnitA0External protection device activatedExternal protection device connected to the terminal strip T1-T2 of indoor unit is activated✓✓✓A1Malfunction of indoor unit PCBMalfunction due to noise Defect of indoor unit PCB✓✓✓✓A3Malfunction of drain level control systemDrain piping clogging, improper drain piping work Defect of drain pump Defect of float switch✓✓✓A4Malfunction of freezing protectionShortage of water volume Low water temperature setting Defect of 26WL Defect of water temperature thermistor✓A5High pressure control in heating, freeze-up protection control in coolingClogged air filter of indoor unit and short-circuit Defect of indoor unit heat exchanger thermistor✓A6Fan motor locked, overload, overcurrentDefect of connector contact Defect of indoor unit PCBDefect of fan motor✓✓✓✓A7Malfunction of swing flap motorFailure of swing flap motor Defect of indoor unit PCB Jammed swing mechanism/blade✓✓A8Malfunction of power supplyOvercurrent of AC input

Defect of power supply voltage

✓✓A9Malfunction of electronic expansion valve driveDefect of electronic expansion valve coil

Defect of indoor unit PCB Defect of connector contact

✓✓AAHeater overheat26WH is activated✓AFMalfunction of a humidifier systemWater leakage of humidifier (option)

Failure of swing float switch Improper drain piping incline

✓✓AHMalfunction of dust collector of air cleanerDefect of dust collecting element Defect of high voltage power supply unitStained insulator part Defect of indoor unit PCB✓✓✓AJMalfunction of capacity setting (Indoor unit PCB)Capacity setting adaptor is not installed when replacing PCB Defect of indoor unit PCB✓✓✓C1Failure of transmission (between indoor unit PCB and fan PCB)Defect of transmission of fan motor control driver✓✓C4Malfunction of liquid pipe thermistor for heat exchangerDefect of connector contact

Defect of liquid pipe thermistor for heat exchanger

✓✓✓✓C5Malfunction of gas pipe thermistor for heat exchangerDefect of connector contact

Defect of gas pipe thermistor for heat exchanger

✓✓✓C6Malfunction of fan motor control driverDefect of fan motor sensor system Defect of fan motor control driver✓✓C7Front panel driving motor faultDefect of front panel driving motor Defect of limit switch✓C9Malfunction of suction air thermistorDefect of connector contact Defect of thermistor for suction air✓✓✓✓CAMalfunction of discharge air thermistorDefect of connector contact

Defect of thermistor for discharge air

✓✓CCMalfunction of humidity sensor systemDefect of connector contact Defect of humidity sensor✓✓CJMalfunction of thermostat sensor in remote controllerDefect of remote controller thermistor Malfunction due to noise Defect of remote controller PCB✓✓✓Outdoor UnitE0Protection devices actuated (unified)Protection device connected to outdoor PCB actuated Defect of protection device connector contact✓✓✓E1Defect of outdoor unit PCBMalfunction due to noise Defect of outdoor unit PCB✓✓✓✓✓E3Actuation of high pressure switch (HPS)Dirty outdoor unit heat exchanger and suction filter Defect of HPS Clogged refrigerant piping Defect of connector contact✓✓✓✓E3System No.1

Actuation of high pressure switch (HPS)

Dirty outdoor unit heat exchanger Clogged refrigerant piping Defect of HPSShortage of water volume Defect of connector contact✓Outdoor UnitE4Actuation of low pressure switch (LPS)Clogged refrigerant piping Shortage of gas

Defect of connecting connector Defect of outdoor unit PCB

✓✓✓✓E5Overheat of inverter compressor motorShortage of refrigerant amount Defect of connector contact Leakage of four way valve✓✓E5Inverter compressor motor lockInverter compressor lock Incorrect wiring✓✓✓E6STD compressor motor overcurrent/lockClosed stop valve STD compressor lock✓✓✓✓E6System No.1 Compressor overcurrentDefect of EXP. valve Defect of compressorShortage of refrigerant amount✓E7Malfunction of outdoor unit fan motorFaulty contact of fan motor connector

Defect of fan motor Defect of fan motor driver

✓✓✓✓✓E8Overcurrent of inverter compressorDefect of compressor Defect of outdoor unit PCB Defect of inverter main circuit capacitor Defect of power transistor✓E9Malfunction of electronic expansion valve coilDefect of electronic expansion valve Defect of connector contact Defect of outdoor unit PCB✓✓✓✓EAMalfunction of four way valveDefect of four way valve Defect of outdoor unit PCBShortage of gas Defect of thermistor✓ECMalfunction of entering water temperatureMalfunction of cooling water temperature

Defect of thermistor Defect of outdoor unit PCB

✓EFMalfunction of thermal storage unitDefect of electronic expansion valve of thermal storage unit Defect of thermal storage PCB✓F3Malfunction of discharge pipe temperatureShortage of gas

Defect of connector contact

Clogged refrigerant piping Defect fo discharge pipe thermistor✓✓✓✓✓F6Abnormal high pressure in coolingDefect of outdoor unit fan motor Defect of electronic expansion valve Defect of heat exchanger thermistor Defect of outdoor unit PCB✓F6Refrigerant overchargedRefrigerant overcharged Disconnection of heat exchanger thermistorDisconnection of outdoor air thermistor Disconnection of liquid pipe thermistor✓✓H0Malfunction of sensor system of compressorHarness is disconnected, or defective connection Defect of PCB✓H1Malfunction of humidifier unit damperDefect of limit switch Defect of damper✓H3Malfunction of high pressure switch (HPS)Defect of high pressure switch Broken wire

Defect of connector contact Defect of outdoor unit PCB

✓✓✓✓H4Malfunction of low pressure switch (LPS)Defect of low pressure switch Broken wire

Defect of connector contact Defect of outdoor unit PCB

✓✓H5Malfunction of compressor motor overload thermistorDefect of connector contact

Defect of compressor motor overload thermistor

✓H6Malfunction of position detection sensorFaulty contact of compress or cable

Defect of compressor Defect of outdoor unit PCB

✓H7Malfunction of outdoor fan motor signalFaulty contact of fan wiring Defect of fan motor driverDefect of fan motor✓✓✓H8Malfunction of compressor input (CT) systemDefect of power transistor Defect of reactor

Faulty wiring of inverter system Defect of outdoor unit PCB

✓H9Malfunction of outdoor air thermistorDefect of connector contact Defect of thermistor for outdoor air✓✓✓✓✓HCMalfunction of (hot) water temperature thermistorDefect of connector contact Defect of outdoor unit PCB Defect of thermistor for water temperature✓✓HFAlarm in thermal storage unit with iceThermal storage group defective wiring Defect of setting Excess of thermal storage tank numbers✓✓HJMalfunction of thermal storage tank water levelLow water level Defect of switch setting Water level detecting sensor failure Defect of connector contact✓✓Outdoor UnitJ1Malfunction of pressure sensorDefect of pressure sensor connector contact

Defect of pressure sensor Defect of outdoor unit PCB

✓✓J2Malfunction of current sensor of compressorDefect of current sensor Defect of outdoor unit PCBDefect of compressor✓✓✓✓J3Malfunction of discharge pipe thermistorDefect of connector contact Defect of outdoor unit PCBDefect of discharge pipe thermistor✓✓✓✓✓J4Malfunction of low pressure equivalent saturated temperature sensor systemDefect of connector contact Defect of thermistor Defect of outdoor unit PCB (Multi-split, Super-multi )✓J5Malfunction of suction pipe thermistorDefect of connector contact Defect of outdoor unit PCBDefect of suction pipe thermistor✓✓✓✓✓J6Malfunction of heat exchanger thermistorDefect of connector contact Defect of outdoor unit PCBDefect of heat exchanger thermistor✓✓✓✓✓J7Malfunction of liquid pipe thermistor (Refrigerant circuit and others)Defect of connector contact Defect of outdoor unit PCBDefect of liquid pipe thermistor✓✓✓✓J8Malfunction of liquid pipe thermistor (Refrigerant circuit and others)Defect of connector contact Defect of outdoor unit PCBDefect of liquid pipe thermistor✓J9Malfunction of gas pipe thermistor (Refrigerant circuit and others)Defect of connector contact Defect of outdoor unit PCBDefect of gas pipe thermistor✓✓✓✓JAMalfunction of high pressure sensorDefect of connector contact Defect of outdoor unit PCBDefect of high pressure sensor✓✓✓✓JCMalfunction of low pressure sensorDefect of connector contact Defect of outdoor unit PCBDefect of low pressure sensor✓✓✓✓JEMalfunction of sub-tank thermistorDefect of connector contact Defect of outdoor unit PCBDefect of sub-tank thermistor✓JFMalfunction of heating thermistor for heat exchangerDefect of connector contact Defect of outdoor unit PCBDefect of heat exchanger thermistor✓JHMalfunction of oil temperature thermistorDefect of connector contact Defect of outdoor unit PCBDefect of oil temperature thermistor✓L0Malfunction of inverter systemShortage of power supply capacity Defect of inverter PCBDefect of power transistor✓L1Malfunction of inverter PCBDefect of compressor wiring Blown fuseDefect of outdoor unit fan motor Defect of inverter PCB✓✓L3Electrical box temperature riseFin temperature rise due to short-circuit Defect of power transistorDefect of outdoor unit fan Defect of outdoor unit PCB✓L4Malfunction of inverter radiating fin temperature riseFin temperature rise due to short-circuit Defect of fin thermistor✓✓✓✓L5Inverter instantaneous overcurrent (DC)Closed stop valve Defect of compressor✓✓✓✓L6Inverter instantaneous overcurrent (AC)Overcharge of refrigerant amount Defect of compressorShortage of power supply capacity Defect of inverter unit✓L8Overcurrent of inverter compressorAbnormal high pressure rise due to clogged refrigerant circuit and others Defect of compressor✓✓✓L9Malfunction of inverter compressor startupFaulty of pressure equalization Defect of compressor wiringDefect of compressor✓✓✓LAMalfunction of power transistorDefect of power transistor Defect of inverter PCBDefect of compressor✓LCMalfunction of transmission between outdoor unit PCB and micro-computerDefect of grounding connection Defect of outdoor unit PCBMalfunction due to noise✓LCMalfunction of transmission between control and inverter PCBDefect of connector contact Defect of inverter PCBMalfunction due to noise Defect of outdoor unit control PCB✓✓✓P0Shortage of refrigerant amount (thermal storage unit)Shortage of refrigerant Clogged refrigerant piping✓Outdoor UnitP1Power voltage imbalance, open phaseOpen phase Voltage imbalance between phases Faulty main circuit capacitor Defect of wiring contact✓✓✓✓P2Automatic refrigerant charge operation stopClosed stop valve

Closed valve of refrigerant tank

✓✓P3Malfunction of thermistor in electrical boxElectrical box temperature rise (ambient temperature rise) Defect of fin thermistor Defect of outdoor unit PCB✓✓P4Malfunction of radiating fin temperature sensorDefect of radiating fin thermistor Defect of wiring contact Defect of outdoor unit PCB✓✓✓✓P8Heat exchanger freezing protection during automatic refrigerant charging(Close the refrigerant cylinder. Start again from step 1.)✓✓P9Malfunction of fan motor (humidifier unit)Defect of fan motor Broken relay harnessDefect of outdoor unit PCB Defect of connector contact✓P9Automatic refrigerant charge operation completed—✓✓PABroken wire of heater (humidifier unit)Defect of heater unit Defect of outdoor unit PCBDefect of thermistor✓PAEmpty refrigerant cylinder during automatic refrigerant chargingRefrigerant cylinder of master unit is empty✓✓PCEmpty refrigerant cylinder during automatic refrigerant chargingRefrigerant cylinder of slave unit 2 is empty✓✓PEAutomatic refrigerant charge operation nearly completed—✓✓PHMalfunction of temperature (humidifier unit)Defect of heater unit Defect of thermistorDefect of connector contact Defect of outdoor unit PCB✓PHEmpty refrigerant cylinder during automatic refrigerant chargingRefrigerant cylinder of slave unit 1 is empty✓✓PJMalfunction of capacity setting (Outdoor unit PCB)Capacity setting adaptor is not installed Improper capacity setting adaptor Defect of outdoor unit PCB✓PJImproper combination between inverter and fan driverMistake of inverter PCB Mistake of control PCBMistake of inverter fan PCB✓✓SystemU0Shortage of refrigerantShortage of refrigerant Closed stop valveClogged refrigerant piping✓✓✓✓✓U1Reverse phase, open phaseReverse phase, open phase of power wiring

Wrong wiring Defect of outdoor unit PCB

✓✓✓✓✓U2Defect of power supply voltage or instantaneous power failureDefect of power supply voltage Instantaneous power failure Defect of wiring contact✓✓✓✓U3Check operation not executedCheck operation not executed✓✓U3Malfunction of transmissionMalfunction due to noise Defect of outdoor unit PCBWrong wiring✓U4Malfunction of transmission between indoor and outdoor unitDefect or indoor-outdoor transmission wiring Malfunction due to noise

Defect of indoor unit PCB and outdoor unit PCB

✓✓✓✓✓U5Malfunction of transmission between indoor unit and remote controllerDefect of remote controller wiring Defect of indoor unit PCB Malfunction due to noise Defect of remote controller main/sub setting✓✓✓✓✓✓U6Malfunction of transmission between indoor unitsFaulty wiring

Defect of indoor unit PCB

Malfunction due to noise✓U7Malfunction of transmission between main body micro-computer – INV micro-computerHarness disconnection/broken wire between PCB Defect of outdoor unit PCB✓U7Malfunction of transmission between outdoor unitsDefect of wiring between outdoor units Defect of outdoor unit switch setting Defect of wiring between outdoor – thermal storage units✓✓✓U8Malfunction of transmission between remote controllersDefect of remote controller main/sub setting

Defect of remote controller wiring Defect of remote controller PCB

✓✓✓✓Others77System No. 1

Malfunction of fan inter lock

Defect of relay contact Broken wire✓78System No. 2

Malfunction of fan inter lock

Defect of relay contact Broken wire✓7ASystem No. 2

Malfunction of current sensor of compressor

Defect of current sensor Defect of compressor Defect of outdoor unit PCB✓7CSystem No. 2

Malfunction of pump inter lock

Cooling water pump interlock actuated✓80Malfunction of entering water temperature thermistorDefect of connector contact

Defect of entering water temperature thermistor

✓81Malfunction of leaving water temperature thermistorDefect of connector contact

Defect of leaving water temperature thermistor

✓82System No. 1

Malfunction of refrigerant thermistor

Defect of connector contact Defect of refrigerant thermistor✓83System No. 2

Malfunction of refrigerant thermistor

Defect of connector contact Defect of refrigerant thermistor✓84System No. 1

Malfunction of heat exchanger thermistor

Defect of connector contact

Defect of heat exchanger thermistor

✓85System No. 2

Malfunction of heat exchanger thermistor

Defect of connector contact

Defect of heat exchanger thermistor

✓86System No. 2

Malfunction of discharge pipe thermistor

Defect of connecting connector Defect of discharge pipe thermistor✓88System No. 2

Malfunction of discharge pipe temperature

Shortage of gas Defect of discharge pipe thermistor Defect of connector contact Clogged refrigerant piping✓89Malfunction of brazed-plate heat exchanger freezingDirty heat exchanger Shortage of refrigerant amount Defect of thermistor✓8ASystem No. 2

Malfunction of leaving water temperature thermistor

Defect of connector contact

Defect of leaving water temperature thermistor

✓8ESystem No. 1

Malfunction of suction pipe thermistor 1 for heating

Defect of connector contact Defect of suction pipe thermistor✓8FSystem No. 1

Malfunction of suction pipe thermistor 2 for heating

Defect of connector contact Defect of suction pipe thermistor✓8HAbnormal high hot water temperatureThree-way valve malfunction Defect of thermistor Defect of water temperature setting✓90Abnormal chilled water quantity, abnormal AXPShortage of water volume Disconnection of AXP✓91System No. 2

Malfunction of electronic expansion valve

Defect of connector contact

Defect of electronic expansion valve coil

✓92System No. 2

Malfunction of suction pipe thermistor

Defect of connector contact Defect of suction pipe thermistor✓94Malfunction of transmission (between heat reclaim ventilation unit and fan unit)Defect of fan unit PCB

Defect of connecting wire between (1) and (2)

✓95System No. 1

Malfunction of inverter system

Defect of fan inverter unit✓96System No. 2

Malfunction of inverter system

Defect of fan inverter unit✓97Malfunction of thermal storage unitDefect of thermal storage unit✓98Malfunction of thermal storage brine pumpActuation of thermal storage brine pump overcurrent (OC)✓99Malfunction of thermal storage brine tankLow water level of thermal storage brine tank✓SystemU9Malfunction of transmission (other system)Defect of communication between other indoor unit and outdoor unit Other indoor unit electronic expansion valve failure✓✓UADefect of indoor/outdoor power supplyWrong model connections Wrong PCB connectedImproper power supply Defect of PCB✓UAMalfunction of field settingMalfunction of field setting by remote controller

Defect of remote controller wiring Defective connection of optional device Defect of indoor unit PCB

✓UAImproper combination of indoor and outdoor unitsExcess of connected indoor units Malfunction of field setting Uncanceled service mode Defect of outdoor unit PCB✓✓✓UARemote temperature setting wire disconnectionRemote temperature setting wire disconnection Defect of connector contact✓UCMalfunction of setting of centralized controller addressAddress duplication of centralized controller✓✓✓UEMalfunction of transmission between indoor unit and centralized controllerMalfunction of wiring between indoor unit and centralized controller Defect of setting of group number Defect of indoor unit PCB✓✓✓✓✓UFWiring and piping mismatchImproper connection of transmission wiring between indoor-outdoor units and outdoor-outdoor units✓✓✓UHMalfunction of systemImproper connection of transmission wiring between indoor- outdoor units and outdoor-outdoor units Defect of indoor and outdoor unit PCB (RA: Mismatching indoor and outdoor units, Defect of voltage, Freeze protection in other indoor unit(k)✓✓UJMalfunction of transmission (Accessory devices)Defect of accessory devices Faulty wiring✓✓M1Malfunction of centralized remote controller PCBDefect of centralized remote controller PCB✓✓✓✓✓✓M8Malfunction of transmission between optional controllers for centralized controlOther centralized control power disconnection Centralized control reset switch ON Defect of transmission wiring Central remote controller address change✓✓✓✓✓✓MAImproper combination of optional controllers for centralized controlImproper combination of optional controllers for centralized control More than one master controller is connected

Faulty setting of centralized control Defect of centralized control

✓✓✓✓✓✓MCAddress duplication, improper settingAddress duplication of central remote controller✓✓✓✓✓✓Others60External protection device actuatedActuation of external protection device

Defect of output signal wiring Defect of control PCB

✓64Malfunction of indoor air thermistorDefect of connecting connector Defect of thermistor for indoor air Defect of control PCB✓65Malfunction of outdoor air thermistorDefect of connector contact Defect of control PCBDefect of outdoor air thermistor✓6AMalfunction of damper systemDefect of connector contact Defect of damper motorDefect of limit switch Defect of control PCB✓70System No. 2 Compressor overloadShortage of refrigerant amount Defect of connector contact Leakage of four way valve✓71System No. 2 Compressor overcurrentShortage of refrigerant amount Short-circuit Defect of compressor✓72System No. 2

Fan motor overcurrent

Defect of fan motor connector contact

Defect of fan motor Defect of PCB

✓73System No. 2

Malfunction of high pressure (HPS) actuated

Dirty heat exchanger Clogged refrigerant piping Defect of HPSShortage of water volume Defect of connector contact✓74System No. 2

Malfunction of low pressure switch (LPS)

Clogged refrigerant piping Shortage of gasDefect of connector contact Defect of LPS✓75System No. 2

Malfunction of low pressure sensor

Defect of connector contact Defect of PCBDefect of low pressure sensor✓76System No. 2

Malfunction of high pressure sensor

Defect of connector contact Defect of PCBDefect of high pressure sensor✓