Daikin Error Codes (Malfunction Self-Diagnosis and Troubleshooting)

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Malfunction (Error) codeMalfunction ContentsSupposed causesObjects
RASkyAirVRVPackageHRVChiller
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

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