LG Air Conditioner Error Code E231

E231 indicates a fault with the condenser outlet temperature sensor on the main outdoor unit. The control board has detected either a short circuit or an open circuit on that sensor circuit. This typically points to a disconnected connector, damaged wiring, or a failed thermistor. The system may shut down to protect the compressor until the fault is resolved.

It is not recommended to continue operating the unit with E231 active. The condenser outlet temperature sensor is used by the control board to manage safe operating conditions for the compressor and refrigerant circuit. Without accurate sensor data, the system cannot properly protect itself, and continued operation could lead to compressor damage or additional component failures.

Repair cost depends on the root cause. If the connector simply needs to be reseated, the only cost is a service call, which typically ranges from $75 to $150. Replacing the COND OUT thermistor sensor generally costs between $50 and $150 for the part plus labor. If the outdoor PCB requires replacement, total costs can range from $300 to $700 or more depending on the unit model and labor rates in your area.

A homeowner can safely check whether the sensor connector has simply come loose at the outdoor PCB, which is a no-cost fix if that is the only problem. However, measuring thermistor resistance, tracing a wiring fault, or replacing the sensor or PCB requires basic electrical knowledge and a multimeter. If you are not comfortable working inside the outdoor unit or reading resistance values, a licensed HVAC technician should handle the diagnosis.

A power reset may temporarily clear the error display, but if the sensor, connector, or wiring fault is still present, the E231 code will return once the unit restarts and the PCB re-checks the sensor circuit. A reset is useful for confirming whether the fault is intermittent, but it does not repair the underlying problem.