Troubleshooting 
Electrical Control  241 
2.2. Self-diagnosis 
Indoor unit’s LED indication 
During malfunction or protection, the indicators and digital LED displays as follow: 
For A5 Duct, HSPD, Ceiling &floor type: 
No
Malfunction or protection  Operation
Timer
Def/Fan
Alarm
Digital LED Display 
1  T1 temperature sensor open or short circuit   
X  ☆  X  X 
E2 
2  T2 temperature sensor open or short circuit   
☆  X  X  X 
E3 
3  T3 temperature sensor open or short circuit  X  X  ☆  X  E4 
4  Indoor EEPROM malfunction 
☆  ☆ 
X  X 
E7 
O (on)      X(off)    ☆(flash at 5Hz)   
Note: Digital display is available for duct type. 
 
For Super-slim 4-way Cassette Type: 
NO.
Malfunction 
Running 
lamp 
Timer 
lamp 
Defrosting 
lamp 
Alarm 
lamp 
Display(digital 
tube) 
1 
T1 temperature sensor open or short circuit   
X  ☆  X  X  E2 
2 
T2 temperature sensor open or short circuit   
☆  X  X  X  E3 
3  T3 temperature sensor open or short circuit  X  X  ☆  X  E4 
4  Indoor EEPROM malfunction  ☆  ☆  X  X  E7 
5  Water level alarm  X  X  X  ☆  E8 
6 
Communication  error  between  auto-lifting 
panel and slim cassette   
☆  X  ☆  ☆  F0 
7 
Auto-lifting panel  is  faulty (for  slim  cassettes 
with an auto-lifting panel) 
X  ☆  ☆  ☆  F1 
8 
Auto-lifting  panel  is  not  closed  (for  slim 
cassettes with an auto-lifting panel) 
X  O  ☆  ☆  F2 
O (on)      X(off)    ☆(flash at 5Hz) 
For Compact cassette Type: 
NO.
Malfunction 
Running 
lamp 
Timer 
lamp 
Defrosting 
lamp 
Alarm 
lamp 
1 
T1 temperature sensor open or short circuit   
X  ☆  X  X 
2 
T2 temperature sensor open or short circuit   
☆  X  X  X 
3 
T3 temperature sensor open or short circuit 
X  X  ☆  X 
4  Indoor EEPROM malfunction  ☆  ☆  X  X 
5  Water level alarm  X  X  X  ☆ 
O (on)      X(off)    ☆(flash at 5Hz) 
For A6 Duct: 
Malfunction
 
Error Code  Timer Lamp
(flashes) 
Indoor EEPROM malfunction  E0  X  1 
T1 temperature sensor open or short circuit    E4  X  5 
T2 temperature sensor open or short circuit    E5  X  6 
Refrigerant leakage detection  EC  X  7 
Water level alarm malfunction
EE  X  8 
T3 temperature sensor open or short circuit    F2  O
 
3 
Dual chips communication malfunction  FA  O  11