59 Carrier AC error codes and troubleshooting

Table of Contents

A few people whatsapp us last week to ask for carrier air conditioning fault codes. Below are almost the full list of carrier air conditioner error codes.

Carrier air conditioner error code DN

Communication error between main board and EXV.

Carrier air conditioner error code E0

Indoor unit EEPROM parameter error.

Timer lamp status: off
Operation lamp blinking: 1 time

Carrier AC error code E0 troubleshooting procedure:

Carrier air conditioner error code E0 troubleshooting

Carrier air conditioner error code E1

Indoor / outdoor units communication error.

Timer lamp status: off
Operation lamp blinking: 2 times

Carrier AC error code E1 troubleshooting procedure:

Carrier air conditioner error code E2

Zero-crossing signal error.

Carrier air conditioner error code E3

Indoor fan speed has been out of control.

Timer lamp status: off
Operation lamp blinking: 4 times

Carrier AC error code E3 troubleshooting procedure:

Carrier air conditioner error code E4

Indoor room temperature sensor T1 open circuit or short circuit.

Timer lamp status: off
Operation lamp blinking: 5 times

Carrier AC error code E4 troubleshooting procedure:

Carrier air conditioner error code E5

Evaporator coil temperature sensor T2 open circuit or short circuit.

Timer lamp status: off
Operation lamp blinking: 6 times

Carrier AC error code E5 troubleshooting procedure:

Carrier air conditioner error code E6

Open or short circuit of room or evaporator coil temperature sensor.

Carrier air conditioner error code E7

Outdoor fan speed has been out of control.

Carrier AC error code E7 troubleshooting procedure:

Carrier air conditioner error code E8

System overload protection.

Carrier air conditioner error code E9

Cold blow protection.

Carrier air conditioner error code EC

Refrigerant leakage detection.

Timer lamp status: off
Operation lamp blinking: 7 times

Carrier air conditioner error code EE

Memory card error.

Carrier air conditioner error code EN

Frequency limitation for module circuit protection.

Carrier air conditioner error code EU

Frequency limitation for module temperature protection.

Carrier air conditioner error code F0

Pump down mode.

Carrier air conditioner error code F1

Outdoor ambient temperature sensor T4 open circuit or short circuit.

Timer lamp status: light
Operation lamp blinking: 2 times

Carrier air conditioner error code F2

Condenser coil temperature sensor T3 open circuit or short circuit.

Timer lamp status: light
Operation lamp blinking: 3 times

Carrier air conditioner error code F3

Compressor discharge temperature sensor T5 open circuit or short circuit.

Timer lamp status: light
Operation lamp blinking: 4 times

Carrier AC error code F3 troubleshooting procedure:

Carrier air conditioner error code F4

Outdoor unit EEPROM parameter error.

Timer lamp status: light
Operation lamp blinking: 5 times

Carrier air conditioner error code F5

Outdoor fan speed has been out of control.

Timer lamp status: light
Operation lamp blinking: 6 times

Carrier air conditioner error code F6

Frequency limitation for overload protection.

Carrier air conditioner error code F7

Cooling oil return cycle.

Carrier air conditioner error code F8

Frequency limitation for system circuit protection.

Carrier air conditioner error code F9

Frequency limitation for module circuit protection.

Carrier air conditioner error code FH

Frequency limitation for freeze protection.

Carrier air conditioner error code H1

Defrost or heating oil return cycle.

Carrier air conditioner error code H3

Compressor overheat protection.

Carrier air conditioner error code H5

IPM Protection.

Main checking point:

  • Is the input voltage of the unit within the acceptable range?
  • Is the compressor connected correctly?
  • Is the compressor winding resistance correct?
  • Are the heat exchangers clean / unblocked?
  • Is the refrigerant charge correct?

Carrier AC error code H5 troubleshooting procedure:

Carrier air conditioner error code H7

Compressor speed reduction.

Carrier air conditioner error code HC

PFC protection malfunction.

Main checking points:

  • Is the power supply correct?
  • Is the reactor broken or miss-wired?

Carrier AC error code HC troubleshooting procedure:

Carrier air conditioner error code HE

Compressor demagnetizing protection.

Carrier air conditioner error code L9

Compressor high voltage protection.

Carrier air conditioner error code LC

Compressor start-up failure.

Main checking points:

  • Is the stop duration of the compressor is correct?
  • Is the compressor connected properly?
  • Is the compressor broken?
  • Is the refrigerant charge amount too great?

Carrier AC error code LC troubleshooting procedure:

Carrier air conditioner error code LD

Compressor phase loss protection.

Carrier air conditioner error code LE

Compressor stalling.

Carrier air conditioner error code LF

Compressor over-speed protection.

Carrier air conditioner error code LP

Indoor and outdoor units mismatch.

Carrier air conditioner error code P0

IBM malfunction or IGBT over-strong current protection.

Timer lamp status: flash
Operation lamp blinking: 1 time

Carrier AC error code P0 troubleshooting procedure:

Carrier air conditioner error code P1

Over voltage or too low voltage protection.

Timer lamp status: flash
Operation lamp blinking: 2 times

Carrier AC error code P1 troubleshooting procedure:

Carrier air conditioner error code P2

High temperature protection of compressor top diagnosis and solution.

Timer lamp status: flash
Operation lamp blinking: 3 times

Carrier AC error code P2 troubleshooting procedure:

Carrier air conditioner error code P4

Inverter compressor drive error.

Timer lamp status: flash
Operation lamp blinking: 5 times

Carrier AC error code P4 troubleshooting procedure:

Carrier air conditioner error code P5

Compressor current protection.

Carrier air conditioner error code P6

Communication error between the inverter drive and main board.

Carrier air conditioner error code P7

Heat sink temperature sensor malfunction.

Carrier air conditioner error code P8

IPM over temperature protection.

Carrier air conditioner error code P9

Open contactor.

Carrier air conditioner error code PA

Input current protection.

Carrier air conditioner error code PC

Current sensor malfunction.

Carrier air conditioner error code PD

Current sensor miss-wiring protection.

Carrier air conditioner error code PF

Inverter board ambient temperature sensor malfunction.

Carrier air conditioner error code PH

High voltage protection.

Carrier air conditioner error code PL

Low voltage protection.

Carrier air conditioner error code PP

Abnormal input AC voltage.

Carrier air conditioner error code PU

Capacitor charging malfunction.

Carrier air conditioner error code A5

Condenser coil inlet temp sensor malfunction.

Carrier air conditioner error code A7

Condenser outlet temperature sensor malfunction.

Carrier air conditioner error code U1

Compressor phase detection malfunction.

Carrier air conditioner error code U3

Low DC bus voltage.

How to remove Carrier air conditioner outdoor unit?

Total Time: 35 minutes

  1. Remove top cover and wiring cover

    How to remove Carrier air conditioner outdoor unit step 1

    Before disassembly, remove screws retaining the wiring cover, lift the cover upward to remove it. Remove screws retaining the top cover, lift the top cover upward to remove it.

  2. Remove front grille and front panel

    How to remove Carrier air conditioner outdoor unit step 2

    Remove the screws retaining the front grille to the front panel. Remove the front grille. Then remove the screws retaining the panel, lift it upward to loosen the clasp on the right side, rotate it to the left and then remove the front panel.

  3. Remove right and left side panels

    How to remove Carrier air conditioner outdoor unit step 3

    Remove the screws retaining the right side panel to the chassis, the valve support and the electric box, then remove the right side panel. Then remove the screws retaining the left side panel to the chassis, then remove the left side panel.

  4. Remove the fan blade

    How to remove Carrier air conditioner outdoor unit step 4

    Remove the nut retaining the blade to the motor shaft, then remove the fan blade.

    Remove the four (4) screws retaining the motor; disconnect the motor wiring, then remove the motor.

    Remove the two (2) screws retaining the motor support; then lift the motor support upwards to remove it

  5. Remove control box assembly

    How to remove Carrier air conditioner outdoor unit step 5

    Remove the screws retaining the control box sub-assembly; loosen the wire bundle; remove the wiring terminals and then lift the control box upwards to remove it.

  6. Remove sound shield

    How to remove Carrier air conditioner outdoor unit step 6

    Carefully remove the sound shield from around the compressor.

  7. Remove reactor

    How to remove Carrier air conditioner outdoor unit step 7

    Remove screws holding the reactor to the compressor partition; then remove the reactor.

  8. Remove 4-way valve

    How to remove Carrier air conditioner outdoor unit step 8

    Reclaim system refrigerant charge.

    Cut all lines connected to 4-way valve; disconnect solenoid coil wiring and remove 4-way valve from unit.

  9. Remove electronic expansion valves and shut-off valves

    How to remove Carrier air conditioner outdoor unit step 9

    Remove the solenoid coils from the electronic expansion vlaves. Cut all lines connecting the valves to the system and remove the valves.

  10. Remove the service valve support assembly

    How to remove Carrier air conditioner outdoor unit step 10

    Remove the screws retaining the valve support to the chassis; then remove the valve support assembly.

  11. Remove compressor partition

    Remove screws retaining the partition and then remove the partition.

  12. Remove compressor

    How to remove Carrier air conditioner outdoor unit step 12

    Remove three (3) nuts from compressor mounting bolts, then lift compressor from base pan.

  13. Remove condenser

    How to remove Carrier air conditioner outdoor unit step 13

    Remove the screws retaining the support and condenser assembly. Then remove the support.

    Remove the condenser from the base pan.

How to disassembly and assembly Carrier air conditioner compressor?

Make sure that there is no refrigerant in pipe system and the power supply is cut off before disassembling the compressor.

1. Disconnect the power cord

How to disassembly and assembly Carrier air conditioner compressor step 1
  • Remove the fixed screws on the power cord by using a screwdriver.
  • Draw out the power cord.

Note: Please note the color of each power cord and also the corresponding terminal number when removing the power cord in case of misconnection.

2. Disassemble the pipeline connected with compressor

How to disassembly and assembly Carrier air conditioner compressor step 2

Disconnect the pipeline connected with compressor.

3. Remove the bad compressor

How to disassembly and assembly Carrier air conditioner compressor step 3
  • Remove the bolts retaining the compressor.
  • Remove the bad compressor from the bottom plate.

4. Place the new compressor on the bottom plate and connect the suction inlet and discharge outlet with the pipe system

How to disassembly and assembly Carrier air conditioner compressor step 4
  • Place the compressor on the bottom plate.
  • Tighten the nuts.

How to disassembly and assembly Carrier air conditioner 4-way valve?

1. Remove the 4-way valve coil

How to disassembly and assembly Carrier air conditioner 4-way valve step 1
  • Remove the screws on the fixed coil by using a screwdriver.
  • Remove the 4-way valve coil.

2. Remove 4-way valve

How to disassembly and assembly Carrier air conditioner 4-way valve step 2

Reclaim all refrigerant charge in system. Cut all line connections to 4-way valve and remove from unit.

3. Replace the 4-way valve

How to disassembly and assembly Carrier air conditioner 4-way valve step 3
  • Place the new 4-way valve in the right place.
  • Reweld the new 4-way valve with the pipeline

4. Install the 4-way valve coil

  • Replace the 4-way valve coil in place
  • Tighten the screws with a screwdriver.

How to disassembly and assembly Carrier air conditioner electronic expansion valve?

1. Remove the electronic expansion valve coil

Remove the electronic expansion valve coil by rotating it until the lock is unfixed.

2. Remove the electronic expansion valve

How to disassembly and assembly Carrier air conditioner electronic expansion valve step 1

Cut all lines to the electronic expansion valves then remove.

3. Replace the electronic expansion valve

How to disassembly and assembly Carrier air conditioner electronic expansion valve step 2

Place the new electronic expansion valve in the right place.

4. Reconnect the electronic expansion valve with the pipeline

How to disassembly and assembly Carrier air conditioner electronic expansion valve step 3

Reconnect the electronic expansion valve with the pipeline by welding.

5. Install the electronic expansion valve coil

Set the electronic expansion valve coil on the valve body and adjust the lock to the right place.

How to disassembly and assembly Carrier air conditioner vapor liquid separator?

1. Disconnect the liquid separator and the connected pipeline

Disconnect the liquid separator and the connected pipeline.

2. Remove the liquid separator

How to disassembly and assembly Carrier air conditioner vapor liquid separator step 2
  • Remove the bolt retaining the liquid separator
  • Remove the liquid separator from the middle baffle.

3. Fix the new liquid separator and connect it with the pipeline

How to disassembly and assembly Carrier air conditioner vapor liquid separator step 3
  • Place the new liquid separator on the middle baffle.
  • Tighten the bolt and reconnect the new liquid separator with the pipeline by welding.

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