Common LG Mini Split Error Codes

Below, you’ll find two tables. The first covers indoor unit error codes, the second covers outdoor unit error codes. Together, they represent a broad reference to help you identify and interpret any errors you might encounter on your LG mini split system. Each error code points to a particular concern—anything from a simple disconnected thermistor wire to a more involved compressor fault.

Before diving into the tables, it’s useful to understand the blinking LED system:

• On indoor units, you may see two LEDs:
  • LED1 (Heating LED)
  • LED2 (Cooling LED)
• On outdoor units, you typically have two PCB LEDs, often labeled as a Green LED and a Red LED.

Each error code corresponds to how many times these LEDs blink in sequence. For example, if your indoor unit is flashing the Heating LED three times and the Cooling LED once, that might correspond to a code 31. Some codes appear only on the indoor unit or only on the outdoor unit; others can appear on both, indicating the same or similar root cause.

Why These Codes Matter

• Early Detection: Error codes are your system’s way of telling you something isn’t working correctly. Recognizing a problem early can protect your unit from more serious damage.
• Targeted Troubleshooting: Rather than guessing what’s wrong, error codes narrow down potential causes, saving you time and possibly money.
• Safe Maintenance: Some codes point to electrical or mechanical concerns that require professional intervention. Knowing what a code indicates ensures you won’t attempt risky DIY repairs that could void warranties or cause injury.

General Guidelines for Handling Error Codes

1. Power Cycle the System: In some cases, turning the power to the mini split off for a few minutes and then switching it back on can reset minor issues, such as communication errors.
2. Check Simple Fixes First: Some codes might be triggered by dirty filters, obstructed vents, or partially disconnected cables. Always inspect your unit for obvious problems—like a blocked airflow path—before delving deeper.
3. Use Caution Around Electrical Components: If you aren’t trained in HVAC or electrical systems, do not remove panels or probe wiring. You may risk electrical shock or damage to sensitive circuit boards.
4. Contact a Professional: If the error code suggests a major malfunction—especially if it involves the compressor, a short circuit, or other high-voltage components—call a licensed HVAC technician.

Below are the official LG mini split error codes, drawn from the company’s reference materials.

Indoor Unit Error Codes

How to Interpret Indoor Unit LED Blinks

• Observe Heating LED (LED1) and Cooling LED (LED2) on your indoor unit.
• A number like “2X” means the LED blinks twice in succession, then pauses.
• If a code has something like “2X / 1X,” it means LED1 blinks twice, LED2 blinks once, and then this pattern repeats.

Many of the error codes above can indicate issues that actually lie in the outdoor unit, but the indoor control board is typically where you see the blinking sequence or code readout. For instance, a DC voltage problem with the compressor (Error 21, 28, 29, etc.) still shows up as a blinking pattern on the indoor unit.

Common Troubleshooting Tips for Indoor Unit Codes

• Thermistor Errors (Codes 1, 2, 6, 12, 40, 41, 44, 45, 46, 48, 65): Thermistors are temperature sensors. If the system reports they are disconnected or shorted, it often points to a wiring problem, a loose connection, or a faulty sensor. Try checking the wires going to these sensors (if you are comfortable doing so), ensuring they’re properly attached and not physically damaged.
• Communication Failures (Codes 5, 53): These usually signal a wiring or control board issue between the indoor and outdoor unit. Confirm that communication cables are intact and properly connected. Sometimes power surges or electrical storms can trigger these errors.
• Fan or Motor Lock (Code 10): This could happen if something physically obstructs the indoor blower fan or if the fan motor has developed a fault.
• Voltage and Current Errors (Codes 22, 23, 25, 31): These suggest the unit is drawing an incorrect amount of power or the voltage supply is abnormal. In these cases, you may want to check your home’s electrical supply or call a professional.

What to Do After Identifying an Error Code

After you’ve identified an error code, here are some steps you can follow:

1. Check for Simple Causes:
   • Ensure that no objects are blocking air intake or exhaust.
   • Confirm that circuit breakers are not tripped.
   • Verify that filters are clean and correctly installed.
2. Power Down and Restart:
   • Switch off the power to both the indoor and outdoor units at the main breaker.
   • Wait at least three to five minutes to allow the system to discharge.
   • Restore power and watch for the error code to reappear.
3. Observe the System’s Behavior:
   • Does the error code come back immediately?
   • Does the unit run normally for a while and then flash an error?
   • Is there any unusual noise from the compressor, fan motor, or refrigerant lines?
4. Consult the Official Manual:
   • In addition to these charts, refer to your specific LG mini split model’s user manual or installation guide.
   • The manual often includes model-specific troubleshooting procedures and disclaimers about what homeowners can safely do.
5. Call a Professional:
   • If the error code indicates a major failure or if you cannot resolve the issue by simple checks, contact a licensed HVAC technician.
   • Trying advanced repairs on your own could void the warranty or cause further damage.

Preventive Measures to Avoid Future Errors

• Schedule Regular Maintenance: At least once or twice a year, have a professional inspect your unit. This includes cleaning coils, checking refrigerant levels, and inspecting electrical components.
• Keep the Outdoor Unit Clear: Debris such as leaves, dirt, or snow can obstruct the outdoor coil. A simple clean-up around your outdoor unit can prevent many airflow or temperature-related faults.
• Monitor Voltage Stability: If you live in an area with frequent power fluctuations, consider installing a dedicated surge protector or voltage regulator. This helps safeguard the sensitive electronics in your mini split system.
• Change Filters Consistently: Dirty filters not only strain the indoor unit but can cause temperature sensor errors and lead to poor airflow, which might eventually trigger error codes.
• Stay Vigilant: Pay attention to unusual sounds, smells, or performance dips. Many times, the system tries to compensate for minor faults before triggering an error code. Early awareness can prevent more serious breakdowns.

When to Seek Professional Help

While some troubleshooting steps (like cleaning filters or clearing debris) are manageable for most homeowners, many of the error codes listed point toward electrical or mechanical failures that require specialized tools and expertise. If you see codes related to compressor faults, thermistor errors you can’t resolve by checking connections, or repeated low/high voltage issues, it’s wise to contact a professional.

Attempting DIY repairs on components like the inverter board, the compressor, or the refrigerant lines can be dangerous. It may also violate local regulations or void your warranty if you’re not a certified technician. Always prioritize your safety and the longevity of your LG mini split system by knowing when to call in an expert.

Final Thoughts

LG mini split systems are designed with sophisticated onboard diagnostics to help you quickly pinpoint and address problems. While some errors can be easily resolved by adjusting settings or performing basic maintenance, others are indicators of more significant issues that require professional attention. By consulting the error code tables and following the guidelines provided above, you’ll be better prepared to keep your mini split running smoothly and efficiently—especially in the varying climate conditions we experience across the United States.

Remember, these charts and tips are meant to serve as a reference guide, not an exhaustive service manual. Always defer to official LG documentation specific to your model and, when in doubt, seek professional assistance. With the right care and periodic check-ups, your LG mini split can offer you many years of reliable and energy-efficient comfort.

(This guide is based on official LG sources and is for informational purposes only. Always follow local codes, regulations, and professional advice for any HVAC work.)