Simple Self-Diagnosis by Malfunction Code
Malfunction
code
Malfunction Contents
Supposed causes
Objects
RA
SkyAir
VR
V
Pa
c
k
a
g
e
Heat rec
laim ventilator
Chiller
F
an Coil
Outdoor Unit
P2
Automatic refrigerant charge
operation stop
The stop valve is not opened
Closed valve of refrigerant tank
k k k
k
P3
Malfunction of thermistor in switch
box
Defective connection of thermistor
Defective reactor thermistor
Defective inverter PCB
k k k k
k
P4
Malfunction of radiation fi n
temperature sensor
Defective radiation fi n temperature thermistor
Defective inverter PCB
Defective INV. compressor
Defective fan motor
k k k k
k
P8
Heat exchanger freezing protection
during automatic refrigerant
charging
(Close the refrigerant cylinder. Start again from step 1.)
k k k
P9
Malfunction of fan motor
(humidifi er unit)
Defective fan motor
Defective outdoor unit PCB
Broken relay harness
Defective connector contact
k
P9
Automatic refrigerant charge
operation completed
—
k k k k
PA
Refrigerant cylinder during
automatic refrigerant charging
Refrigerant cylinder of master unit is empty
k k k
PA
Broken wire of heater
(humidifi er unit)
Defective heater unit
Defective thermistor
Defective outdoor unit PCB
k
PC
Refrigerant cylinder during
automatic refrigerant charging
Refrigerant cylinder of slave unit 2 is empty
k k
PE
Automatic refrigerant charge
operation nearly completed
—
k k k
PH
Refrigerant cylinder during
automatic refrigerant charging
Defective heater unit
Defective connector contact
Defective thermistor
Defective outdoor unit PCB
k
k k
PJ
Malfunction of capacity setting
(Outdoor unit PCB)
Capacity setting adaptor is not installed
Improper capacity setting adaptor
Defective outdoor unit PCB
k
PJ
Improper combination between
inverter and fan driver
Mis-matching of type of PCB
Improper (or no) fi eld setting after replacing outdoor unit
main PCB
k k k
k
System
U0
Shortage of refrigeran
Refrigerant shortage and refrigerant clogging (wrong
piping)
Defective thermistor
Defective low pressure sensor
Defective outdoor unit main PCB
k k k k
k
U1
Reverse phase, open phase
Power supply reverse phase
T phase open phase
Defective outdoor unit PCB (A1P)
k k k k k k k
U2
Malfunction of power supply or
instantaneous power failure
Abnormal power supply voltage
Instantaneous power failure
Defective main circuit wiring
k k k k
k k
U3
Check operation not executed or
transmission error
Check operation is not executed.
k k k k k k k
U4
Malfunction of transmission
between indoor and outdoor unit
Short circuit in indoor-outdoor or outdoor-outdoor
transmission wiring (F1 / F2), or wrong wiring
Outdoor unit power supply is OFF
System address does not match
Defective indoor unit PCB
Defective outdoor unit PCB
k k k k k k k
U5
Malfunction of transmission
between indoor unit and remote
controller
Transmission error between indoor unit and remote
controller
Connection of 2 main remote controllers (when using 2
remote controllers)
Defective indoor unit PCB
Defective remote controller PCB
Transmission error caused by noise
k k k k
k k
U6
Malfunction of transmission
between indoor units
Faulty wiring
External factor (Noise etc.)
Defective indoor unit PCB
k k
k k
Malfunction
code
Malfunction Contents
Supposed causes
Objects
RA
SkyAir
VR
V
Pa
c
k
a
g
e
Heat rec
laim ventilator
Chiller
F
an Coil
System
U7
Malfunction of transmission
between outdoor units or outdoor
storage unit
Connection error of transmission wirings between outdoor
unit and external control adaptor for outdoor unit
Connection error of transmission wirings between outdoor
units
Defective outdoor unit PCB
k
k k
k k
U8
Malfunction of transmission
between remote controllers
Transmission error between main and sub remote
controller
Connection between sub remote controllers
Defective remote controller PCB
k k k k k k
U9
Malfunction of transmission (other
system)
Transmission error between other indoor and outdoor units
Defective electronic expansion valve of other indoor unit
Defective indoor unit PCB of other indoor unit
Improper connection of transmission wiring between
indoor and outdoor unit
k k k
k k
UA
Defect of indoor/outdoor power
supply
Wrong model connections
Improper power supply
Wrong PCB connected
Defective PCB
k
UA
Improper combination of indoor
and outdoor units
Excess of connected indoor units
Defective outdoor unit PCB
Mismatch of the refrigerant type of indoor and outdoor unit
Setting of outdoor unit PCB was not carried out after
replacing to spare PCB
k k k
k
UA
Remote temperature setting wire
disconnection
Remote temperature setting wire disconnection
Defective connector contact
k
UC
Malfunction of setting of centralized
control equipment address
Address duplication of centralized control equipment
Defective indoor unit PCB
k k k k k k
UE
Malfunction of transmission
between indoor unit and
centralized control equipment
Transmission error between optional controllers for
centralized control equipment and indoor unit
Connector for setting main controller is disconnected.(or
disconnection of connector for independent / combined
use changeover switch.)
Defective PCB for central remote controller
Defective indoor unit PCB
k k k k k k
UF
System is not set yet
Improper connection of transmission wiring between
indoor-outdoor units and outdoor-outdoor units
Failure to execute check operation
Defective indoor unit PCB
Stop valve is not opened
k k k k
UH
Malfunction of system
Improper connection of transmission wiring between
indoor-outdoor units and outdoor-outdoor units
Defective indoor unit PCB
Defective outdoor unit PCB
k
k k
UJ
Malfunction of transmission
(accessory device)
Defect of accessory devices
Faulty wiring
k k k k
k
Other
s
60
External protection device
activated (Heat reclaim ventilator)
Actuation of external protection device
Defective output signal wiring
Defective control PCB
k
64
Malfunction of indoor air thermistor
(Heat reclaim ventilator)
Defective connector contact
Defective indoor air thermistor
Defective control PCB
k
65
Malfunction of outdoor air
thermistor (Heat reclaim ventilator)
Defective connector contact
Defective outdoor air thermistor
Defective control PCB
k
6A
Malfunction of damper system
(Heat reclaim ventilator)
Defective connector contact
Defective limit switch
Defective damper motor
Defective control PCB
k
70
System No. 2
Compressor overheat
Shortage of refrigerant amount
Defective connector contact
Leakage of four way valve
k
71
System No. 2
Compressor overcurrent
Shortage of refrigerant amount
Short circuit
Defective compressor
k
