
Simple Self-Diagnosis by Malfunction Code
Malfunction
code
Malfunction Contents Supposed causes
Objects
RA
SkyAir
VRV
Package
Heat reclaim ventilator
Chiller
Fan Coil
Indoor Unit
A0 External protection device
activated
External protection device connected to the terminal strip
T1-T2 of indoor unit is activated kkk
A1 Malfunction of indoor unit PCB Defective indoor unit PCB
External factor (Noise etc.) kkkkkk
A3 Drain Level Control System
Abnormality
Drain clogging, upward slope, etc.
Defective drain pump
Defective float switch or short circuit connector kkk k k
A4 Malfunction of freezing protection Shortage of water volume
Low water temperature setting
Defective water temperature thermistor kkkk kk
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 kkkk
A6
Malfunction of fan motor Broken wires in, short circuit of, or disconnection of
connectors from the fan motor harness
Defective fan motor
Defective indoor unit PCB
kkkkk
A7
Malfunction of swing flap motor Defective swing flap motor
Defective indoor unit PCB
Defective connection cable
Defective airflow direction adjusting flap-cam
kk
A8 Malfunction of power supply or AC
input overcurrent
Defective power supply voltage
Defective connection on signal line
Defective wiring kk k
A9 Malfunction of electronic expansion
valve
Defective electronic expansion valve coil
Defective indoor unit PCB
Defective relay cables kkkkk
AA Heater overheat 26WH is activated kk
AF Malfunction of a humidifier system Humidifier unit (optional accessory) leaking
Defective drain piping (upward slope, etc.)
Defective indoor unit PCB kk k
AH
Malfunction of dust collector of air
cleaner
Defect of dust collecting element
Stained insulator part
Defect of high voltage power supply unit
Defect of indoor unit PCB
kkk k
AJ Malfunction of capacity setting
(Indoor unit PCB)
The capacity setting adaptor was not installed when
replacing PCB.
Defective indoor unit PCB kkk
C1 Failure of transmission (between
indoor unit PCB and sub PCB)
Defective connection of the connector between indoor
unit PCB kk
C4 Malfunction of liquid pipe
thermistor for heat exchanger
Defective thermistor for liquid pipe
Defective indoor unit PCB
Defective connector contact kkkkkkk
C5 Malfunction of gas pipe thermistor
for heat exchanger
Defective thermistor for gas pipe
Defective indoor unit PCB
Defective connector contact k kkkk
C6 Malfunction of fan motor sensor or
fan control driver
Defective fan PCB
Defective connection of capacity setting adaptor
Field setting error kk
C7 Front panel driving motor fault Defective front panel driving motor
Defective limit switch k
C9 Malfunction of suction air
thermistor
Defective thermistor for suction air
Defective indoor unit PCB
Defective connector contact kkkkk k
CA Malfunction of discharge air
thermistor
Defective thermistor for discharge air
Defective indoor unit PCB
Defective connector contact k kkk
CC Malfunction of humidity sensor
system
Defective humidity sensor
Defective connector contact kk k
CJ Room temperature thermistor in
remote controller abnormality
Defective room temperature thermistor in remote controller
Defective remote controller PCB
External factor (Noise etc.) kkkk k
Malfunction
code
Malfunction Contents Supposed causes
Objects
RA
SkyAir
VRV
Package
Heat reclaim ventilator
Chiller
Fan Coil
Outdoor Unit
E0 Protection devices activated
(unified)
Protection device connected to outdoor unit PCB actuated
Defective protection device connector contact kk k
E1 Defective outdoor unit PCB Defective outdoor unit PCB
Defective connection of inside/ outside relay wires kkkk k
E3
Actuation of high pressure switch
(HPS)
Dirty outdoor unit heat exchanger
Defective high pressure switch
Clogged refrigerant piping
Defective connector contact
kkkk
E3
System No.1
Actuation of high pressure switch
(HPS)
Dirty outdoor unit heat exchanger
Shortage of water volume
Clogged refrigerant piping
Defective connector contact
Defective HPS
k
E4
Actuation of low pressure switch
(LPS)
Abnormally drop in low pressure
Defective low pressure sensor
Defective outdoor unit PCB
Defective connector contact
kkk k
E5
Inverter compressor motor or
overheat
Inverter compressor lock
High differential pressure
Defective inverter PCB
UVW connection error
Defective connector contact
kkkk k
E6 STD compressor motor
overcurrent/lock
Defective compressor
Defective control PCB
The stop valve is not opened
kkkk
E6 System No.1 Compressor
overcurrent
Defective electronic expansion valve
Shortage of refrigerant amount
Defective compressor
k
E7
Malfunction of outdoor unit fan
motor system
Fan motor failure
Neglect to connect or defective connection of harness/
connector between the fan motor and the PCB
Fan does not rotate due to foreign matters caught in it
kkkk k
E8
Overcurrent of inverter compressor Defective compressor
Defective inverter main circuit capacitor
Defect of outdoor unit PCB
Defect of power transistor
kk
E9 Malfunction of electronic expansion
valve coil
Disconnection of connectors from electronic expansion valves
Defective electronic expansion valve coil
Defective outdoor unit control PCB
kkk k
EA
Malfunction of four way valve or
cool/heat switchin
Defective four way valve
Shortage of gas
Defective outdoor unit PCB
Defective thermistor
k
EC Malfunction of entering water
temperature
Cooling water temperature abnormality
Defective outdoor unit PCB
Defective thermistor
k
F3
Malfunction of discharge pipe
temperature
Defective discharge pipe thermistor
Abnormal discharge pipe temperature
Defective outdoor unit control PCB
Defective connector contact
kkkk k
F6
Abnormal high pressure or
refrigerant overcharged
Refrigerant overcharged
Disconnection of heat exchanger deicer thermistor
Disconnection of outdoor air thermistor
Disconnection of liquid pipe temperature thermistor
Defective outdoor unit PCB
kkkk
H0 Malfunction of sensor system of
compressor
Harness is disconnected, or defective connection
Defective PCB kk
H1 Malfunction of room temperature
sensor or humidifier unit damper
Defective limit switch
Defective damper kk
H3
Malfunction of high pressure switch
(HPS)
Defective high pressure switch
Broken wire
Defective outdoor unit PCB
Defective connector contact
kkkk k
H4
Malfunction of low pressure switch
(LPS)
Defective low pressure switch
Broken wire
Defective outdoor unit PCB
Defective connector contact
kk k
I