LG Air Conditioner Error Code E126

E126 indicates a discharge temperature sensor error on the indoor unit. The control board has detected that the discharge sensor signal is either shorted (resistance too low) or open (no resistance reading at all). This prevents the system from obtaining a valid discharge air temperature, and normal operation may be suspended until the fault is corrected.

Operating the unit while E126 is active is not recommended. The discharge sensor is part of the system's temperature monitoring logic, and running without a valid sensor reading can cause the unit to operate outside safe parameters. The system may shut itself down automatically, but it is better to address the fault before continuing use.

A power reset by turning the unit off at the breaker for a few minutes may temporarily clear the error code, but if the underlying sensor or wiring fault is still present, the code will return once the unit restarts and the control board re-evaluates the sensor signal. A reset alone is not a repair, and the root cause must be diagnosed and corrected for the error to stay cleared.

A knowledgeable DIYer can check the sensor connector for looseness or corrosion and reseat it, which sometimes resolves the error. Testing the sensor with a multimeter to check its resistance is also within reach for someone comfortable with basic electrical diagnostics. However, replacing the sensor or the indoor control board typically requires disassembling the indoor unit and working with the electrical components, which many homeowners prefer to leave to a qualified technician.

If only the discharge sensor needs replacement, parts and labor typically range from around $75 to $200 depending on the unit model and local labor rates. If the indoor control board is also found to be faulty, the total cost can rise to a range of $200 to $500 or more. Getting a diagnosis from a technician first helps avoid paying for unnecessary parts.