10 Troubleshooting
Outdoor and indoor alarm codes
SMGB0099 rev.0 - 12/2016
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10
10.4  Outdoor and indoor alarm codes
The following alarm codes are displayed in the 7-segments on the PCB of the outdoor units.
Code 
number
Category Abnormality Cause
1
Indoor unit
Activation of protection device  
(oat switch)(*)
Failure of fan motor, drain discharge, PCB, relay, 
oat switch activated (High water level in drain pan, 
abnormality of drain pipe, oat switch or drain pan)
2
Outdoor unit
Activation of protection device  
(high pressure cut)
Activation of PSH, locked motor, abnormal operation 
in the power supply phase. Failure of fan motor, drain 
discharge, PCB, relay, oat switch activated. (Pipe 
clogging, excessive refrigerant, inert gas mixing, fan 
motor locking at cooling operation)
3
Transmission
Abnormal transmission between outdoor and 
indoor units
Incorrect wiring. Loose terminals, Failure of PCB (control 
or inverter). Tripping of fuse. Power supply OFF.
4
Abnormal transmission between inverter 
PCB (DIP-IPM) and outdoor unit PCB 
(PCB1)
Transmission failure between inverter PCBs.  
(Loose connector, wire breaking, blowout of fuse)
5
Power supply
Reception of abnormal operation code for 
detection of power source phase 
(Abnormal power source)
Power source with abnormal wave pattern. Main power 
supply phase is reversely connected or one phase is not 
connected.  
(units with power supply 3N~ 400V 50Hz only)
6
Voltage
Excessively low voltage or excessively high 
voltage for the inverter
Voltage drop in power supply. Incorrect wiring or 
insufcient capacity of power supply wiring.
7
Cycle
Decrease in discharge gas superheat 
(TdSH)
Excessive refrigerant charge, failure of thermistor, 
incorrect wiring, incorrect piping connection, expansion 
valve locking at opened position (disconnected 
connector).
8
Excessively high discharge gas temperature 
at the top of compressor
Insufcient refrigerant charge, refrigerant leakage. 
Expansion valve closed or clogged.
11
Indoor units 
sensor
Air inlet thermistor(*)
Failure of thermistor, sensor, connection.  
(Incorrect wiring, disconnected wiring, wire breaking, 
short circuit).
12
Air outlet thermistor(*)
13
Freeze protection thermistor(*)
14
Gas piping thermistor(*)
16
Remote thermistor
17
Thermistor of RCS
19
Fan motor
Activation of the protection device for the 
indoor fan motor(*)
Failure of fan motor or CB activation (overcurrent) for 
RPI-(16.0/20.0)FSN3PE(-f)
20
Outdoor unit 
sensor
Compressor thermistor
Incorrect wiring, disconnected wiring, broken cable, short 
circuit.
21
High pressure sensor
22
Thermistor for outdoor ambient temperature 
(THM7)
23
Thermistor for discharge gas temperature 
(THM9)
24
Thermistor for evaporating temperature 
(THM8)
Incorrect wiring, disconnected wiring, wire breaking, 
short circuit, fan motor locking at heating operation.
29
Low pressure sensor
Incorrect wiring, disconnected wiring, broken cable, short 
circuit.
31
System
Incorrect capacity setting or combined 
capacity between outdoor and indoor units
Incorrect capacity code setting, excessive or insufcient 
indoor unit total capacity code
32
Incorrect setting signal from another Indoor 
Unit in same system (RPK only)
Abnormality of another indoor unit in the same  
refrigerant cycle (failure of power source,  
abnormality of PCB)
35
Incorrect indoor unit number setting 
(Incorrect IU addversing)
Duplication of indoor unit number , number of indoor 
units over specications.
36
Incorrect of indoor unit combination
"Indoor Unit is designed for other refrigerant (R22 or 
R407C)."
38
Abnormality of picking up circuit for 
protection (Outdoor unit)
Failure of indoor unit PCB, incorrect wiring, connection 
to PCB in indoor unit.