Daikin Air Conditioners Error Codes

Malfunction Error Code								Malfunction Contents									Potential causes											Systems
																												RA	SkyAir			VRV	Package	HRV		Chiller
Indoor Unit		A0						External protection device activated									External protection device connected to the terminal strip T1-T2 of indoor unit is activated												✓			✓	✓
		A1						Malfunction of indoor unit PCB									Malfunction due to noise Defect of indoor unit PCB											✓	✓			✓	✓
		A3						Malfunction of drain level control system									Drain piping clogging, improper drain piping work Defect of drain pump Defect of float switch											✓	✓			✓
		A4						Malfunction of freezing protection									Shortage of water volume Low water temperature setting Defect of 26WL Defect of water temperature thermistor																			✓
		A5						High pressure control in heating, freeze-up protection control in cooling									Clogged air filter of indoor unit and short-circuit Defect of indoor unit heat exchanger thermistor											✓
		A6						Fan motor locked, overload, overcurrent									Defect of connector contact Defect of indoor unit PCB						Defect of fan motor					✓	✓			✓	✓
		A7						Malfunction of swing flap motor									Failure of swing flap motor Defect of indoor unit PCB Jammed swing mechanism/blade												✓			✓
		A8						Malfunction of power supply									Overcurrent of AC input Defect of power supply voltage												✓			✓
		A9						Malfunction of electronic expansion valve drive									Defect of electronic expansion valve coil Defect of indoor unit PCB Defect of connector contact															✓	✓
		AA						Heater overheat									26WH is activated																			✓
		AF						Malfunction of a humidifier system									Water leakage of humidifier (option) Failure of swing float switch Improper drain piping incline												✓			✓
		AH						Malfunction of dust collector of air cleaner									Defect of dust collecting element Defect of high voltage power supply unit						Stained insulator part Defect of indoor unit PCB					✓	✓			✓
		AJ						Malfunction of capacity setting (Indoor unit PCB)									Capacity setting adaptor is not installed when replacing PCB Defect of indoor unit PCB												✓			✓	✓
		C1						Failure of transmission (between indoor unit PCB and fan PCB)									Defect of transmission of fan motor control driver												✓			✓
		C4						Malfunction of liquid pipe thermistor for heat exchanger									Defect of connector contact Defect of liquid pipe thermistor for heat exchanger											✓	✓			✓	✓
		C5						Malfunction of gas pipe thermistor for heat exchanger									Defect of connector contact Defect of gas pipe thermistor for heat exchanger											✓				✓	✓
		C6						Malfunction of fan motor control driver									Defect of fan motor sensor system Defect of fan motor control driver												✓			✓
		C7						Front panel driving motor fault									Defect of front panel driving motor Defect of limit switch											✓
		C9						Malfunction of suction air thermistor									Defect of connector contact Defect of thermistor for suction air											✓	✓			✓	✓
		CA						Malfunction of discharge air thermistor									Defect of connector contact Defect of thermistor for discharge air															✓	✓
		CC						Malfunction of humidity sensor system									Defect of connector contact Defect of humidity sensor											✓	✓
		CJ						Malfunction of thermostat sensor in remote controller									Defect of remote controller thermistor Malfunction due to noise Defect of remote controller PCB												✓			✓	✓
Outdoor Unit		E0						Protection devices actuated (unified)									Protection device connected to outdoor PCB actuated Defect of protection device connector contact												✓			✓				✓
		E1						Defect of outdoor unit PCB									Malfunction due to noise Defect of outdoor unit PCB											✓	✓			✓	✓			✓
		E3						Actuation of high pressure switch (HPS)									Dirty outdoor unit heat exchanger and suction filter Defect of HPS Clogged refrigerant piping Defect of connector contact											✓	✓			✓	✓
		E3						System No.1 Actuation of high pressure switch (HPS)									Dirty outdoor unit heat exchanger Clogged refrigerant piping Defect of HPS						Shortage of water volume Defect of connector contact													✓
Outdoor Unit		E4						Actuation of low pressure switch (LPS)									Clogged refrigerant piping Shortage of gas Defect of connecting connector Defect of outdoor unit PCB												✓			✓	✓			✓
		E5						Overheat of inverter compressor motor									Shortage of refrigerant amount Defect of connector contact Leakage of four way valve											✓								✓
		E5						Inverter compressor motor lock									Inverter compressor lock Incorrect wiring												✓			✓	✓
		E6						STD compressor motor overcurrent/lock									Closed stop valve STD compressor lock											✓	✓			✓	✓
		E6						System No.1 Compressor overcurrent									Defect of EXP. valve Defect of compressor					Shortage of refrigerant amount														✓
		E7						Malfunction of outdoor unit fan motor									Faulty contact of fan motor connector Defect of fan motor Defect of fan motor driver											✓	✓			✓	✓			✓
		E8						Overcurrent of inverter compressor									Defect of compressor Defect of outdoor unit PCB Defect of inverter main circuit capacitor Defect of power transistor											✓
		E9						Malfunction of electronic expansion valve coil									Defect of electronic expansion valve Defect of connector contact Defect of outdoor unit PCB												✓			✓	✓			✓
		EA						Malfunction of four way valve									Defect of four way valve Defect of outdoor unit PCB					Shortage of gas Defect of thermistor						✓
		EC						Malfunction of entering water temperature									Malfunction of cooling water temperature Defect of thermistor Defect of outdoor unit PCB															✓
		EF						Malfunction of thermal storage unit									Defect of electronic expansion valve of thermal storage unit Defect of thermal storage PCB															✓
		F3						Malfunction of discharge pipe temperature									Shortage of gas Defect of connector contact					Clogged refrigerant piping Defect fo discharge pipe thermistor						✓	✓			✓	✓			✓
		F6						Abnormal high pressure in cooling									Defect of outdoor unit fan motor Defect of electronic expansion valve Defect of heat exchanger thermistor Defect of outdoor unit PCB											✓
		F6						Refrigerant overcharged									Refrigerant overcharged Disconnection of heat exchanger thermistor					Disconnection of outdoor air thermistor Disconnection of liquid pipe thermistor										✓	✓
		H0						Malfunction of sensor system of compressor									Harness is disconnected, or defective connection Defect of PCB											✓
		H1						Malfunction of humidifier unit damper									Defect of limit switch Defect of damper											✓
		H3						Malfunction of high pressure switch (HPS)									Defect of high pressure switch Broken wire Defect of connector contact Defect of outdoor unit PCB											✓	✓			✓	✓
		H4						Malfunction of low pressure switch (LPS)									Defect of low pressure switch Broken wire Defect of connector contact Defect of outdoor unit PCB												✓			✓
		H5						Malfunction of compressor motor overload thermistor									Defect of connector contact Defect of compressor motor overload thermistor											✓
		H6						Malfunction of position detection sensor									Faulty contact of compress or cable Defect of compressor Defect of outdoor unit PCB											✓
		H7						Malfunction of outdoor fan motor signal									Faulty contact of fan wiring Defect of fan motor driver					Defect of fan motor							✓			✓	✓
		H8						Malfunction of compressor input (CT) system									Defect of power transistor Defect of reactor Faulty wiring of inverter system Defect of outdoor unit PCB											✓
		H9						Malfunction of outdoor air thermistor									Defect of connector contact Defect of thermistor for outdoor air											✓	✓			✓	✓			✓
		HC						Malfunction of (hot) water temperature thermistor									Defect of connector contact Defect of outdoor unit PCB Defect of thermistor for water temperature												✓			✓
		HF						Alarm in thermal storage unit with ice									Thermal storage group defective wiring Defect of setting Excess of thermal storage tank numbers												✓			✓
		HJ						Malfunction of thermal storage tank water level									Low water level Defect of switch setting Water level detecting sensor failure Defect of connector contact												✓			✓
Outdoor Unit		J1						Malfunction of pressure sensor									Defect of pressure sensor connector contact Defect of pressure sensor Defect of outdoor unit PCB												✓			✓
		J2						Malfunction of current sensor of compressor									Defect of current sensor Defect of outdoor unit PCB						Defect of compressor						✓			✓	✓			✓
		J3						Malfunction of discharge pipe thermistor									Defect of connector contact Defect of outdoor unit PCB						Defect of discharge pipe thermistor					✓	✓			✓	✓			✓
		J4						Malfunction of low pressure equivalent saturated temperature sensor system									Defect of connector contact Defect of thermistor Defect of outdoor unit PCB (Multi-split, Super-multi )											✓
		J5						Malfunction of suction pipe thermistor									Defect of connector contact Defect of outdoor unit PCB						Defect of suction pipe thermistor					✓	✓			✓	✓			✓
		J6						Malfunction of heat exchanger thermistor									Defect of connector contact Defect of outdoor unit PCB						Defect of heat exchanger thermistor					✓	✓			✓	✓			✓
		J7						Malfunction of liquid pipe thermistor (Refrigerant circuit and others)									Defect of connector contact Defect of outdoor unit PCB						Defect of liquid pipe thermistor						✓			✓	✓			✓
		J8						Malfunction of liquid pipe thermistor (Refrigerant circuit and others)									Defect of connector contact Defect of outdoor unit PCB						Defect of liquid pipe thermistor						✓
		J9						Malfunction of gas pipe thermistor (Refrigerant circuit and others)									Defect of connector contact Defect of outdoor unit PCB						Defect of gas pipe thermistor					✓	✓			✓	✓
		JA						Malfunction of high pressure sensor									Defect of connector contact Defect of outdoor unit PCB						Defect of high pressure sensor						✓			✓	✓			✓
		JC						Malfunction of low pressure sensor									Defect of connector contact Defect of outdoor unit PCB						Defect of low pressure sensor						✓			✓	✓			✓
		JE						Malfunction of sub-tank thermistor									Defect of connector contact Defect of outdoor unit PCB						Defect of sub-tank thermistor									✓
		JF						Malfunction of heating thermistor for heat exchanger									Defect of connector contact Defect of outdoor unit PCB						Defect of heat exchanger thermistor									✓
		JH						Malfunction of oil temperature thermistor									Defect of connector contact Defect of outdoor unit PCB						Defect of oil temperature thermistor									✓
		L0						Malfunction of inverter system									Shortage of power supply capacity Defect of inverter PCB						Defect of power transistor									✓
		L1						Malfunction of inverter PCB									Defect of compressor wiring Blown fuse						Defect of outdoor unit fan motor Defect of inverter PCB						✓			✓
		L3						Electrical box temperature rise									Fin temperature rise due to short-circuit Defect of power transistor						Defect of outdoor unit fan Defect of outdoor unit PCB					✓
		L4						Malfunction of inverter radiating fin temperature rise									Fin temperature rise due to short-circuit Defect of fin thermistor											✓	✓			✓	✓
		L5						Inverter instantaneous overcurrent (DC)									Closed stop valve Defect of compressor											✓	✓			✓	✓
		L6						Inverter instantaneous overcurrent (AC)									Overcharge of refrigerant amount Defect of compressor						Shortage of power supply capacity Defect of inverter unit									✓
		L8						Overcurrent of inverter compressor									Abnormal high pressure rise due to clogged refrigerant circuit and others Defect of compressor												✓			✓	✓
		L9						Malfunction of inverter compressor startup									Faulty of pressure equalization Defect of compressor wiring						Defect of compressor						✓			✓	✓
		LA						Malfunction of power transistor									Defect of power transistor Defect of inverter PCB						Defect of compressor									✓
		LC						Malfunction of transmission between outdoor unit PCB and micro-computer									Defect of grounding connection Defect of outdoor unit PCB						Malfunction due to noise					✓
		LC						Malfunction of transmission between control and inverter PCB									Defect of connector contact Defect of inverter PCB						Malfunction due to noise Defect of outdoor unit control PCB						✓			✓	✓
		P0						Shortage of refrigerant amount (thermal storage unit)									Shortage of refrigerant Clogged refrigerant piping															✓
Outdoor Unit		P1						Power voltage imbalance, open phase									Open phase Voltage imbalance between phases Faulty main circuit capacitor Defect of wiring contact												✓			✓	✓			✓
		P2						Automatic refrigerant charge operation stop									Closed stop valve Closed valve of refrigerant tank															✓	✓
		P3						Malfunction of thermistor in electrical box									Electrical box temperature rise (ambient temperature rise) Defect of fin thermistor Defect of outdoor unit PCB											✓	✓
		P4						Malfunction of radiating fin temperature sensor									Defect of radiating fin thermistor Defect of wiring contact Defect of outdoor unit PCB											✓	✓			✓	✓
		P8						Heat exchanger freezing protection during automatic refrigerant charging									(Close the refrigerant cylinder. Start again from step 1.)															✓	✓
		P9						Malfunction of fan motor (humidifier unit)									Defect of fan motor Broken relay harness					Defect of outdoor unit PCB Defect of connector contact						✓
		P9						Automatic refrigerant charge operation completed									—															✓	✓
		PA						Broken wire of heater (humidifier unit)									Defect of heater unit Defect of outdoor unit PCB					Defect of thermistor						✓
		PA						Empty refrigerant cylinder during automatic refrigerant charging									Refrigerant cylinder of master unit is empty															✓	✓
		PC						Empty refrigerant cylinder during automatic refrigerant charging									Refrigerant cylinder of slave unit 2 is empty															✓	✓
		PE						Automatic refrigerant charge operation nearly completed									—															✓	✓
		PH						Malfunction of temperature (humidifier unit)									Defect of heater unit Defect of thermistor					Defect of connector contact Defect of outdoor unit PCB						✓
		PH						Empty refrigerant cylinder during automatic refrigerant charging									Refrigerant cylinder of slave unit 1 is empty															✓	✓
		PJ						Malfunction of capacity setting (Outdoor unit PCB)									Capacity setting adaptor is not installed Improper capacity setting adaptor Defect of outdoor unit PCB												✓
		PJ						Improper combination between inverter and fan driver									Mistake of inverter PCB Mistake of control PCB					Mistake of inverter fan PCB										✓	✓
System		U0						Shortage of refrigerant									Shortage of refrigerant Closed stop valve					Clogged refrigerant piping						✓	✓			✓	✓			✓
		U1						Reverse phase, open phase									Reverse phase, open phase of power wiring Wrong wiring Defect of outdoor unit PCB											✓	✓			✓	✓			✓
		U2						Defect of power supply voltage or instantaneous power failure									Defect of power supply voltage Instantaneous power failure Defect of wiring contact											✓	✓			✓	✓
		U3						Check operation not executed									Check operation not executed															✓	✓
		U3						Malfunction of transmission									Malfunction due to noise Defect of outdoor unit PCB					Wrong wiring														✓
		U4						Malfunction of transmission between indoor and outdoor unit									Defect or indoor-outdoor transmission wiring Malfunction due to noise Defect of indoor unit PCB and outdoor unit PCB											✓	✓			✓	✓			✓
		U5						Malfunction of transmission between indoor unit and remote controller									Defect of remote controller wiring Defect of indoor unit PCB Malfunction due to noise Defect of remote controller main/sub setting											✓	✓			✓	✓	✓		✓
		U6						Malfunction of transmission between indoor units									Faulty wiring Defect of indoor unit PCB					Malfunction due to noise										✓
		U7						Malfunction of transmission between main body micro-computer – INV micro-computer									Harness disconnection/broken wire between PCB Defect of outdoor unit PCB											✓
		U7						Malfunction of transmission between outdoor units									Defect of wiring between outdoor units Defect of outdoor unit switch setting Defect of wiring between outdoor – thermal storage units															✓	✓			✓
		U8						Malfunction of transmission between remote controllers									Defect of remote controller main/sub setting Defect of remote controller wiring Defect of remote controller PCB												✓			✓	✓	✓
Others		77						System No. 1 Malfunction of fan inter lock									Defect of relay contact Broken wire																			✓
		78						System No. 2 Malfunction of fan inter lock									Defect of relay contact Broken wire																			✓
		7A						System No. 2 Malfunction of current sensor of compressor									Defect of current sensor Defect of compressor Defect of outdoor unit PCB																			✓
		7C						System No. 2 Malfunction of pump inter lock									Cooling water pump interlock actuated																			✓
		80						Malfunction of entering water temperature thermistor									Defect of connector contact Defect of entering water temperature thermistor																			✓
		81						Malfunction of leaving water temperature thermistor									Defect of connector contact Defect of leaving water temperature thermistor																			✓
		82						System No. 1 Malfunction of refrigerant thermistor									Defect of connector contact Defect of refrigerant thermistor																			✓
		83						System No. 2 Malfunction of refrigerant thermistor									Defect of connector contact Defect of refrigerant thermistor																			✓
		84						System No. 1 Malfunction of heat exchanger thermistor									Defect of connector contact Defect of heat exchanger thermistor																			✓
		85						System No. 2 Malfunction of heat exchanger thermistor									Defect of connector contact Defect of heat exchanger thermistor																			✓
		86						System No. 2 Malfunction of discharge pipe thermistor									Defect of connecting connector Defect of discharge pipe thermistor																			✓
		88						System No. 2 Malfunction of discharge pipe temperature									Shortage of gas Defect of discharge pipe thermistor Defect of connector contact Clogged refrigerant piping																			✓
		89						Malfunction of brazed-plate heat exchanger freezing									Dirty heat exchanger Shortage of refrigerant amount Defect of thermistor																			✓
		8A						System No. 2 Malfunction of leaving water temperature thermistor									Defect of connector contact Defect of leaving water temperature thermistor																			✓
		8E						System No. 1 Malfunction of suction pipe thermistor 1 for heating									Defect of connector contact Defect of suction pipe thermistor																			✓
		8F						System No. 1 Malfunction of suction pipe thermistor 2 for heating									Defect of connector contact Defect of suction pipe thermistor																			✓
		8H						Abnormal high hot water temperature									Three-way valve malfunction Defect of thermistor Defect of water temperature setting																			✓
		90						Abnormal chilled water quantity, abnormal AXP									Shortage of water volume Disconnection of AXP																			✓
		91						System No. 2 Malfunction of electronic expansion valve									Defect of connector contact Defect of electronic expansion valve coil																			✓
		92						System No. 2 Malfunction of suction pipe thermistor									Defect of connector contact Defect of suction pipe thermistor																			✓
		94						Malfunction of transmission (between heat reclaim ventilation unit and fan unit)									Defect of fan unit PCB Defect of connecting wire between (1) and (2)																	✓
		95						System No. 1 Malfunction of inverter system									Defect of fan inverter unit																			✓
		96						System No. 2 Malfunction of inverter system									Defect of fan inverter unit																			✓
		97						Malfunction of thermal storage unit									Defect of thermal storage unit																			✓
		98						Malfunction of thermal storage brine pump									Actuation of thermal storage brine pump overcurrent (OC)																			✓
		99						Malfunction of thermal storage brine tank									Low water level of thermal storage brine tank																			✓
System		U9						Malfunction of transmission (other system)									Defect of communication between other indoor unit and outdoor unit Other indoor unit electronic expansion valve failure															✓	✓
		UA						Defect of indoor/outdoor power supply									Wrong model connections Wrong PCB connected					Improper power supply Defect of PCB						✓
		UA						Malfunction of field setting									Malfunction of field setting by remote controller Defect of remote controller wiring Defective connection of optional device Defect of indoor unit PCB												✓
		UA						Improper combination of indoor and outdoor units									Excess of connected indoor units Malfunction of field setting Uncanceled service mode Defect of outdoor unit PCB															✓	✓	✓
		UA						Remote temperature setting wire disconnection									Remote temperature setting wire disconnection Defect of connector contact																			✓
		UC						Malfunction of setting of centralized controller address									Address duplication of centralized controller												✓			✓	✓
		UE						Malfunction of transmission between indoor unit and centralized controller									Malfunction of wiring between indoor unit and centralized controller Defect of setting of group number Defect of indoor unit PCB												✓			✓	✓	✓		✓
		UF						Wiring and piping mismatch									Improper connection of transmission wiring between indoor-outdoor units and outdoor-outdoor units												✓			✓	✓
		UH						Malfunction of system									Improper 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)				✓	✓
		UJ						Malfunction of transmission (Accessory devices)									Defect of accessory devices Faulty wiring															✓				✓
		M1						Malfunction of centralized remote controller PCB									Defect of centralized remote controller PCB											✓	✓			✓	✓	✓		✓
		M8						Malfunction of transmission between optional controllers for centralized control									Other centralized control power disconnection Centralized control reset switch ON Defect of transmission wiring Central remote controller address change											✓	✓			✓	✓	✓		✓
		MA						Improper combination of optional controllers for centralized control									Improper combination of optional controllers for centralized control More than one master controller is connected Faulty setting of centralized control Defect of centralized control											✓	✓			✓	✓	✓		✓
		MC						Address duplication, improper setting									Address duplication of central remote controller											✓	✓			✓	✓	✓		✓
Others		60						External protection device actuated									Actuation of external protection device Defect of output signal wiring Defect of control PCB																	✓
		64						Malfunction of indoor air thermistor									Defect of connecting connector Defect of thermistor for indoor air Defect of control PCB																	✓
		65						Malfunction of outdoor air thermistor									Defect of connector contact Defect of control PCB					Defect of outdoor air thermistor												✓
		6A						Malfunction of damper system									Defect of connector contact Defect of damper motor					Defect of limit switch Defect of control PCB												✓
		70						System No. 2 Compressor overload									Shortage of refrigerant amount Defect of connector contact Leakage of four way valve																			✓
		71						System No. 2 Compressor overcurrent									Shortage of refrigerant amount Short-circuit Defect of compressor																			✓
		72						System No. 2 Fan motor overcurrent									Defect of fan motor connector contact Defect of fan motor Defect of PCB																			✓
		73						System No. 2 Malfunction of high pressure (HPS) actuated									Dirty heat exchanger Clogged refrigerant piping Defect of HPS					Shortage of water volume Defect of connector contact														✓
		74						System No. 2 Malfunction of low pressure switch (LPS)									Clogged refrigerant piping Shortage of gas					Defect of connector contact Defect of LPS														✓
		75						System No. 2 Malfunction of low pressure sensor									Defect of connector contact Defect of PCB					Defect of low pressure sensor														✓
		76						System No. 2 Malfunction of high pressure sensor									Defect of connector contact Defect of PCB					Defect of high pressure sensor														✓

Daikin Air Conditioner Error Codes Troubleshooting

• No Power/Light Off:

  • Check if the fuse has blown.
  • Ensure power is connected and no power failure occurred.
  • Replace remote controller batteries.
  • Check if the timer is set correctly.

• Not Heating or Cooling Properly:

  • Set temperature and mode correctly.
  • Clean air filters.
  • Ensure nothing is blocking airflow.
  • Close windows and doors.
  • Check if ventilation fan is working.

• Unit Stopped, Light Flashing:

  • Clean air filters and restart.
  • Remove any obstructions around indoor and outdoor units.

• Odour from Unit:

  • Minor ozone smell during purification—harmless.
  • Mould-proof function can cause odour in humid conditions.

• Remote Display Fading:

  • Replace batteries (use alkaline; lasts about a year).

• Operate Without Remote:

  • Press ON/OFF button on the main unit for auto mode.

• Water Leaking Indoors:

  • Turn off and unplug unit.
  • Contact a technician.