Samsung Air Conditioner Error Code E231

E231 indicates a fault in the COND_OUT main temperature sensor circuit at the condenser outlet. The control board has detected a signal voltage either above 4.9V (open circuit, reading as -50 degrees Celsius) or below 0.4V (short circuit, reading as 93 degrees Celsius). Because neither value is a valid operating temperature, the unit stops running to protect the system. The root cause is typically a wiring, connector, or sensor failure.

No. When E231 is active, the unit lacks reliable condenser outlet temperature data, which means the control board cannot properly protect the compressor from overheating or refrigerant pressure extremes. Operating the system in this condition risks compressor damage and potentially costly repairs. The unit should remain off until the sensor circuit is repaired.

Repair costs depend on what component has failed. Reconnecting a loose connector or cleaning corroded pins may cost nothing beyond a service call fee, which typically ranges from $75 to $150. Replacing the COND_OUT temperature sensor is generally inexpensive, with parts usually in the $15 to $50 range plus labor. If the control PCB is at fault, total costs including parts and labor can range from $200 to $600 or more depending on the unit model.

Some causes of E231 are accessible to a knowledgeable DIYer. Checking the sensor connector for loose seating, inspecting the wiring harness for visible damage, and cleaning corroded terminals are tasks that do not require special tools. However, testing sensor resistance accurately requires a multimeter and knowledge of NTC thermistor values, and replacing a control PCB involves working near high-voltage components, which should be left to a certified technician.

A power reset may temporarily clear the error display, but if the underlying sensor circuit fault still exists, the E231 code will return once the unit attempts to operate and re-reads the invalid signal. A reset alone is not a fix. The wiring, connector, and sensor must be inspected and repaired before the error will stay clear.