Fault codes Carrier ALPHA Inverter

7.Troubleshooting
7.1 Indoor Unit Error Display Function

LED4    operation    LED2 defrosting    LED1 timer    LED4 auto

Carrier ALPHA Inverter air conditioning fault codes

LED2LED1 LED3LED4 
defrostTimerAutooperationLED STATUS
XXO*Mold protection
OXX*Compressor top protection against temperature
XOX*Open or short circuit of outdoor temperature sensor
XOO*Over load or too low voltage protection
OOO*Room temperature or evaporator temperature sensor open or
short circuit of
OO**Fan speed beyond control
*XO*Zero-crossing examination error
*OX*Temperature fuse protection
XX**EEPROM data error
*OX*Types doesn't match
****Indoor / outdoor units communication protection

O (on)  X (off) * (flash)
7.2 Outdoor Unit Error Self-diagnosis Display

Outdoor Unit Error:  If L4 flashes at 1 Hz
Outdoor unit works:  L4 on
Outdoor unit Stand by:  If L4 flashes at 0.5Hz