Carrier ACs have a self-diagnostic feature that exhibits the error code on the remote controller and IDU display to enlighten users and service technicians, enabling them to address the issue quickly and efficiently. In addition, the outdoor units in split Air conditioners display the errors associated with the ODU separately.
Carrier Indoor AC unit Error Code List and explanation
Let us discuss the indoor unit error codes first.
Error Code E0 – Operation lamp one-time flash and no timer – Indoor unit EEPROM parameter error
The EEPROM error is a software problem that the AC technician must address. The cause might be a fault in the PCB. So, replacing the PCB is an ideal solution.
Error Code E1 – Operation lamp two times flash and no timer – Communication malfunction between the indoor and outdoor units
The error code E1 is usually an installation fault. The communication between the IDU and ODU can snap. The technician should check for electrical problems and replace the wiring if damaged. There can be a plumbing problem due to broken or disconnected pipes. Reconnecting or replacing them should solve that.
Error Code E3 – Operation lamp four times flash and no timer – Indoor fan speed malfunction
Carrier AC units have fans inside their indoor units. The copper winding can come loose with sustained usage. The capacity can get damaged. There can be an electrical circuit fault. The technician should investigate and take appropriate steps.
Error Code E4 – Operation lamp five times flash and no times – Indoor room temperature sensor T1 malfunction
Sensor malfunctions can occur due to various reasons. For example, there can be a disconnection, a snapped sensor, or a circuit problem. In addition, excessive heat generated by the refrigerant can also cause the sensor to fail. Under such circumstances, replacing the sensor is ideal.
Error Code E5 – Operation lamp six times flash and no timer – Evaporator coil temperature sensor T2 malfunction
The T2 sensor malfunction can happen due to snapped sensor, a disconnection, or a PCB fault. Accordingly, the technician should handle the issue. Replacing the sensor is the best solution.
Error Code EE – Operation lamp eight times flash and no timer – Water level alarm malfunction
The error code EE is observed in cassette and duct-type AC units alone. It indicates that the water tray is full and does not drain properly. The reason could be a choked drain pipe. Users can change the pipe and resolve the matter.
Error Code F1 – Operation lamp two times flash with alarm – Outdoor ambient temperature sensor T4 malfunction
A refrigerant issue can also cause the temperature sensor to fail. Similarly, there can be a disconnection or a PCB fault. Accordingly, the AC technician should handle the issue. The sensor might need replacement if faulty.
Error Code F2 – Operation lamp three times flash with alarm – Condenser coil temperature sensor T3 malfunction
The condenser coil temperature T3 sensor can malfunction due to refrigerant issues, a circuit board problem, or a disconnection. Under such circumstances, the Carrier AC error code F2 flashes on the IDU and remote controller display. The solution is to reconnect the sensor or replace it if faulty. The technician should also look for other faults.
Error Code F3 – Operation lamp four times flash with alarm – Compressor discharge temperature sensor (T5) malfunction
A faulty PCB or a refrigerant issue can cause the T5 sensor to malfunction and flash the Carrier Error Code F3. The solution is to check the refrigerant levels, repair the PCB circuit, and replace the T5 sensor if faulty.
Error Code F4 – Operation lamp five times flash with alarm – Outdoor unit EEPROM parameter error
The EEPROM error can happen because of a faulty PCB. The solution is repairing the circuit or replacing the PCB. The PCB might be under warranty. Users should note the fact and engage with the authorized Carrier AC technician.
Error Code F5 – Operation lamp six times flash with alarm – Outdoor fan speed malfunction
A loose winding or a capacitor failure can cause the outdoor fan to malfunction and rotate at abnormal speeds. The technician should check the wiring, tighten the fan coils, and replace the capacitor if necessary.
Error Code F6 – Operation lamp seven times flash with alarm – Indoor coil outlet pipe sensor malfunction (located on the outdoor unit)
A clogged outlet pipe can snap the sensor and flash the error code F6. The solution is to repair or replace the outlet pipe and reconnect the sensor. Replacing the sensor might be necessary if damaged.
Error Code P0 – Operation lamp one-time flash with alarm – Inverter module IPM malfunction
Users should book a service call and engage with an authorized AC technician to resolve the error.
Error Code P1 – Operation lamp two times flash with alarm – Over-voltage or under-voltage protection issue
Usually, Carrier ACs can function within a wide voltage range. However, the circuit breaker can snap if the voltage exceeds the operational range. The solution is to wait for the voltage to stabilize and reset the circuit breaker. You can also use an external voltage stabilizer as a precautionary measure.
Error Code P4 – Operational lamp with five times flash and alarm – Compressor drive malfunction.
Usually, the compressor does not malfunction easily. Besides, it is under warranty. However, the compressor drive can malfunction and display the error code P4. The solution is to replace the compressor drive and restart the AC.
Error Code P5 – Operational lamp with six times flash and alarm – Indoor unit mode conflict
The Carrier AC technician is the ideal person to resolve the issue.
Error Code P6 – Operational lamp with seven times flash and alarm – Low-pressure protection
A refrigerant issue can cause the low-pressure protection circuit breaker to trip. The solution is to check and correct the refrigerant levels before resetting the circuit breaker.
Here are some error codes associated with the Carrier AC ODU.
Error Code E0 – Outdoor unit EEPROM parameter error
EEPROM parameter error is a software issue that requires the Carrier AC technician to check the PCB and replace it if necessary.
Error Code E2 – Communication problem between the IDU and ODU
The technician should check for snapped wires or a broken pipe connection between the IDU and the ODU. The remedy is to replace the wiring or the pipes.
Error Code E3 – Communication malfunction between the IPM board and outdoor main control board
There can be a loose connection or a faulty PCB. The solution is to investigate the reasons properly and take appropriate action.
Error Code E4 – Malfunctioning of the outdoor sensor (T2B, T3, T4, or T5)
A problem with the outdoor sensor can result in the flashing of the error code E4. The sensor might have disconnected or become faulty. Accordingly, the technician should reconnect or replace the respective sensor.
Error Code E5 – Over voltage or under voltage protection issue
Voltage fluctuation can cause the error code E5. The solution is to connect an external voltage stabilizer to regulate the voltage levels.
Error Code E6 – PFC module protection issue
The PFC module is a crucial hardware component of the Carrier AC. A fault with the PFC module can result in the tripping of the circuit breaker. Users should not reset the circuit breaker before rectifying the issue. The solution is to replace the PFC module.
Error Code E8 – Outdoor fan speed malfunction
A PCB fault, a loose winding, or a capacitor failure can cause the outdoor fan to spin abnormally. The technician should rectify the fault accordingly.
Error Code F1 – Indoor unit A coil outlet temperature sensor malfunction
Replace or reconnect the sensor. Please check for refrigerant pressure and leakage.
Error Code F2 – Indoor unit B coil outlet temperature sensor malfunction
The solution is to replace or reconnect the sensor.
Error Code F3 – Indoor unit C coil outlet temperature sensor malfunction
Reconnecting or replacing the sensor can set the matter right.
Error Code F4 – Indoor unit D coil outlet temperature sensor malfunction
The technician should investigate and reconnect or replace the sensor if necessary.
Error Code F5 – Indoor unit E coil outlet temperature sensor malfunction
The solution is to reconnect or replace the faulty sensor.
Error Code P1 – High-pressure protection
The error code P1 can occur if a refrigerant issue leads to tripping the high-production protection circuit breaker. The solution is to check the refrigerant levels and reset the circuit breaker.
Error Code P2 – Low-pressure protection
The error code P2 is the opposite situation of the error code P1. The technician should set things right before resetting the circuit breaker.
Error Code P3 – Current overload protection
The current overload protection circuit breaker can trip if excessive current flows into the machine. The solution is to wait for the power supply to stabilize before resetting the circuit breaker.
Error Code P4 – Compressor discharge temperature protection
A refrigerant issue can cause the compressor discharge temperature protection circuit breaker to trip. Check the refrigerant levels and set them right. Otherwise, the compressor can malfunction and become damaged.
Error Code P5 – Condenser high-temperature protection
The technician should check for refrigerant levels and pressure. The circuit breaker connected to the condenser can break if the temperature exceeds a threshold. The solution is to check the refrigerant levels and reset the circuit breaker.
Error Code P6 – Inverter module IPM protection
The AC technician is the right person to handle this issue. Therefore, users should book a service call and summon the authorized AC mechanic.
Users should not try to rectify the Carrier AC errors themselves. Instead, it is better to contact the service center and book a service appointment with the authorized AC technician.