LG air conditioners display error codes to help you quickly identify and solve common problems. Whether your AC flashes CH 34 or shows a blinking display, decoding these messages can save time and frustration. This list covers the most frequent LG AC error codes, what causes them, and how you can fix each one yourself or know when to call for professional help.
CH 01 to CH 09: Sensor and Thermistor Errors
Many LG AC error codes beginning with CH relate to sensor or thermistor faults. For example, CH 01 indicates an indoor pipe sensor error, while CH 02 signals a problem with the indoor room temperature sensor. These components monitor temperature and help the unit regulate cooling.
Causes often include loose connections, damaged sensor wires, or a failed thermistor. To troubleshoot, first turn off the power. Carefully remove the front panel. Check the affected sensor’s wiring harness for loose plugs or corrosion. If the sensor is dirty, gently clean it. If the code persists, the sensor or thermistor may need replacement. Genuine LG parts are recommended, as incorrect sensors can give false readings and cause further issues.
CH 10 to CH 14: Outdoor Unit Communication and Pressure Issues
Codes like CH 10 (communication error between indoor and outdoor units) and CH 12 (outdoor pipe sensor fault) point to problems outside. Communication errors often mean a broken wire, a problem with the control board, or power interruptions. Pressure-related codes, such as CH 14 (high pressure switch fault), suggest issues like blocked condenser coils or refrigerant overcharge.
For communication errors, visually inspect the connecting cable and terminals for damage or loose contacts. Reset the breaker to see if the code clears. For high pressure faults, check the outdoor unit for dirt or debris blocking airflow and clean as needed. If the code remains, stop using the unit and call a professional, as refrigerant handling and electrical repair require specialized tools and knowledge.
CH 21 and CH 23: Compressor and Inverter Errors
CH 21 indicates a compressor lock or overcurrent, while CH 23 signals inverter module failure. These are critical issues as the compressor is the AC’s heart, and inverter modules control its speed and efficiency.
Common causes include voltage spikes, power outages, or worn-out components. Try resetting power to the unit for at least 10 minutes. If the error returns, avoid running the AC, as operation under these conditions can cause permanent damage. Compressor or inverter repairs are not DIY-friendly; hire an LG-certified technician. They will test windings, inspect the inverter board, and check for refrigerant leaks or blockages that can trigger these codes.
CH 24 and CH 34: Safety and Overheating Warnings
CH 24 means a drain pump malfunction. Water may not be draining from the indoor unit, risking overflow and water damage. CH 34 appears when the safety float switch detects rising water in the drain pan or when the unit overheats due to poor airflow.
For CH 24, inspect the drain pipe for blockages (kinks, algae, or dirt). Remove any clogs and be sure the pipe slopes downward. If the drain pump is making noise or not running, it may need replacement. For CH 34, check that filters are clean and nothing blocks the airflow around the indoor or outdoor unit. If airflow is clear and the code persists, the safety sensors may be faulty and need attention from a technician.
CH 38: Refrigerant Shortage Detected
CH 38 means the system measures low refrigerant pressure, often from a slow leak. If your LG AC is not cooling well and displays this code, it’s likely low on refrigerant.
This isn’t a quick fix at home. First, turn off the unit to protect the compressor. A professional technician must check for leaks using a leak detector, repair the leak, and recharge with the correct type and amount of refrigerant. Do not attempt to add refrigerant yourself, as overcharging or using the wrong type will damage the system and may void your warranty.
FL, F1, F2, and E Series: Filter, Fan, and General Errors
Some LG ACs show codes like FL for a full drain pan (portable models), F1 or F2 for fan motor faults, and E1 for general errors. FL means the internal bucket needs emptying; simply slide it out, drain, and replace.
For fan errors, power off the AC, remove the cover, and clear out any obstructions such as dust buildup or foreign objects. If the fan still won't run, the motor may need lubrication or replacement. For E1 or other general codes, try unplugging the unit for five minutes before restarting. Persistent errors may point to main board issues that require professional diagnosis.
How to Reset Error Codes and When to Call for Help
After addressing the possible cause, you may need to reset your LG AC to clear the error code. Unplug the unit or switch off the breaker for at least five minutes, then restore power. Most codes will reset if the issue is fixed. If the code returns, this means the root cause isn’t resolved.
Call an LG-authorized service technician if error codes keep coming back, if you suspect refrigerant or electrical faults, or if you are uncertain about the diagnosis. Attempting repairs outside your expertise can create bigger problems or void your warranty. Keep a record of when the error appears and what steps you've tried; this helps the technician diagnose faster.
Frequently asked questions
How do I find the error code on my LG AC?
Most LG air conditioners display the error code directly on the digital panel or blink LED lights in a specific pattern when a fault occurs. Refer to your model’s manual for details about indicator lights.
Can I clear LG AC error codes myself?
You can clear codes by fixing the cause and unplugging the unit for five minutes. If the code comes back, professional service is needed.
Are all LG AC error codes the same for every model?
Most codes are similar, but a few codes and their meanings can vary between split, window, and portable AC models. Always check your specific model’s manual.
Will running my AC with an error code damage it?
It can. Some errors, like low refrigerant or compressor faults, can cause expensive damage if ignored. Always address error codes promptly to avoid bigger repairs.