Samsung Air Conditioner Error Code E126

The E126 error code on a Samsung air conditioner indicates a discharge temperature sensor fault, specifically a short circuit or open circuit condition in the sensor circuit. The discharge sensor monitors the refrigerant temperature at the compressor outlet, which is a critical measurement for protecting the compressor from overheating and ensuring the refrigeration cycle operates within safe parameters. When the control board detects that the sensor signal falls outside the expected resistance or voltage range, it triggers the E126 code and typically shuts down or restricts compressor operation.

The two fault conditions covered by this code are electrically distinct. A short circuit means the sensor resistance has dropped too low, pulling the signal voltage toward zero, which the control board interprets as an impossibly low temperature reading. An open circuit means the sensor circuit has been broken entirely, either through a failed sensor element, a broken wire, or a disconnected connector, causing the signal voltage to read at or near the supply reference voltage. Both conditions cause the board to register an out-of-range input and flag the error.

Common root causes include a failed thermistor sensor element, damaged or corroded wiring in the sensor harness, loose or oxidized connector pins at the control board or sensor terminals, and in less common cases, a faulty control board that misreads a valid sensor signal. Because the discharge line operates at elevated temperatures and pressures, sensor wiring in that area can degrade over time due to heat exposure.