Samsung Air Conditioner Error Code 122

Error code 122 indicates a fault with the indoor unit heat exchanger IN temperature sensor. The control board has detected either an open circuit or a short circuit from this sensor, which can be caused by a disconnected connector, a broken wire, or a failed thermistor. The system stops normal operation when this code appears to prevent damage from unmonitored coil temperatures.

It is not advisable to continue running the unit while this code is active. The heat exchanger IN sensor provides critical coil temperature data that the control board uses to prevent freeze-up and overheating. Operating without a functional sensor could lead to further equipment damage or reduced system reliability.

A power reset may temporarily clear the code from the display, but if the underlying fault with the sensor, its wiring, or its connector is still present, the error will return once the unit attempts to operate. The root cause must be diagnosed and corrected for the code to stay cleared permanently.

A knowledgeable DIYer can handle the basic diagnostics, including checking that the sensor connector is fully seated and visually inspecting the wire for damage. Testing the thermistor with a multimeter is also straightforward. However, if the sensor or wiring harness needs to be replaced and involves accessing internal components of the indoor unit, a technician with HVAC experience is recommended.

If only a loose connector is involved, there may be no parts cost at all, just a service call fee ranging from roughly $75 to $150 depending on your location. If the thermistor sensor itself needs replacement, parts typically run in the $15 to $50 range, with total repair costs including labor falling between $100 and $250. A broken wiring harness can add to that cost depending on the extent of the damage.