Fault codes Carrier ALPHA Inverter

7.Troubleshooting
7.1 Indoor Unit Error Display Function

LED4    operation    LED2 defrosting    LED1 timer    LED4 auto

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