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What Do AC Error Codes Mean?

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What Do AC Error Codes Mean?

Posted On: June 2, 2024

What Do AC Error Codes Mean?

Air conditioning (AC) units can display error codes when something goes wrong. These codes are specific to the manufacturer and model of the AC unit, but here are some general explanations for common AC error codes:


General AC Error Codes

  1. E1/E2/E3/E4: These codes often indicate issues with sensors:


    • E1: Room temperature sensor error.
    • E2: Indoor coil sensor error.
    • E3: Indoor fan speed malfunction.
    • E4: Outdoor coil sensor error.
  2. F1/F2/F3: These codes are usually related to the frequency drive or the main control board.


    • F1: Indoor unit PCB (Printed Circuit Board) error.
    • F2: Outdoor unit PCB error.
    • F3: Outdoor ambient temperature sensor error.
  3. H1/H2/H3: These codes generally indicate protection errors.


    • H1: Defrosting mode.
    • H2: Overload protection of the compressor.
    • H3: High-temperature protection of the compressor.
  4. P1/P2/P3: These codes typically relate to pressure or system malfunctions.


    • P1: High pressure protection of the system.
    • P2: Low pressure protection of the system.
    • P3: Protection against lack of refrigerant or malfunction in the refrigerant system.
  5. L1/L2/L3: These codes can be related to electrical issues.


    • L1: Phase loss or imbalance.
    • L2: Overcurrent protection.
    • L3: Voltage error or under-voltage protection.

Manufacturer-Specific Error Codes

LG

  • CH 01: Indoor unit room temperature sensor error.
  • CH 02: Indoor unit pipe temperature sensor error.
  • CH 03: Communication error between indoor and outdoor units.

Daikin

  • U0: Low refrigerant.
  • U4: Transmission error.
  • E1: Circuit board malfunction.

Mitsubishi

  • P1: Abnormal rise in pressure.
  • P8: Outdoor unit air temperature sensor error.
  • E0: Inverter/compressor malfunction.

Samsung

  • E101: Communication error.
  • E121: Indoor temperature sensor error.
  • E154: Outdoor coil sensor error.

What to Do When an Error Code Appears

  1. Consult the Manual: The best source of information is the user manual or service manual for your specific AC model.
  2. Reset the Unit: Sometimes, resetting the unit by turning it off and on again can clear the error.
  3. Check for Obvious Issues: Ensure that filters are clean, vents are not blocked, and that there is no visible damage to the unit.
  4. Call a Professional: If the error persists, it's best to contact a professional technician. They can diagnose and fix the issue safely.

Understanding these codes can help you determine whether the issue is something simple that you can fix yourself or if you need to call a professional for assistance.



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