Samsung Air Conditioner Error Code E256

E256 indicates a compressor OLP (Over-Load Protector) sensor error caused by a signal voltage that is either above 4.95V or below 0.5V when the outdoor temperature is above -20°C. These voltage extremes indicate an open circuit or short circuit condition in the sensor or its wiring. The system disables operation to protect the compressor from running without valid thermal monitoring.

No. The E256 error means the system cannot reliably monitor the compressor's thermal condition, so the unit will typically lock out operation automatically. Attempting to bypass or repeatedly reset the system without fixing the underlying fault risks running the compressor without proper over-temperature protection, which can lead to compressor failure.

Repair costs depend on what component has failed. Replacing the OLP temperature sensor typically ranges from around $50 to $150 for parts and labor. If the outdoor control board is the cause, parts and labor can range from $200 to $500 or more depending on the model and service rates in your area. A diagnostic visit from a technician is usually required to confirm the exact fault before parts are ordered.

A knowledgeable DIYer can inspect and reseat the OLP sensor connector and check the wiring harness for visible damage without special tools. Measuring sensor resistance to confirm whether the thermistor has failed does require a multimeter but is straightforward. Replacing the sensor or outdoor control board involves working inside the outdoor unit, and refrigerant-side work must be handled by a certified technician.

A power reset may temporarily clear the error code, but E256 will return if the root cause has not been repaired. The fault condition is checked continuously when the outdoor temperature is above -20°C, so the code will reappear as soon as the system re-evaluates the sensor signal and finds it out of range. A permanent fix requires repairing or replacing the faulty sensor or wiring.