Samsung Air Conditioner Error Code E251

E251 indicates that the digital compressor discharge temperature sensor circuit has been detected as open or shorted, producing a voltage signal above 4.95V or below 0.4V. This sensor monitors refrigerant temperature leaving the compressor, and the fault is only triggered when outdoor ambient temperature is above -10 degrees Celsius. The system flags this error to protect the compressor from operating without accurate temperature feedback.

It is not recommended to continue running the unit with this error active. The discharge temperature sensor is a key protection input for the compressor, and operating without reliable temperature data risks compressor overheating and potentially severe mechanical damage. The compressor is the most expensive component in the system, so operating through an active protection fault is a significant risk.

A power reset may temporarily clear the error code from the display, but if the underlying fault in the sensor circuit has not been corrected, the E251 error will return once the unit attempts to operate and the outdoor temperature is above -10 degrees Celsius. A reset without diagnosis and repair does not resolve the root cause and can delay proper service.

A homeowner can safely check the visible wiring and connector at the outdoor unit without opening sealed refrigerant circuits. Reseating a loose connector or identifying obvious wire damage is within reach for a careful DIYer. However, testing sensor resistance, replacing components, or working inside the outdoor electrical panel should be done by a qualified technician, as line voltage is present in the outdoor unit.

If the fix is simply reseating a loose connector, the cost may be limited to a service call fee, typically in the range of $75 to $150. Replacing the discharge temperature sensor itself usually adds $50 to $150 in parts. If the outdoor control board requires replacement, total repair costs can range from $300 to $600 or more depending on the model and labor rates in your area.