Samsung Air Conditioner Error Code E402

E402 indicates that the outdoor unit's compressor discharge temperature sensor 1 has detected an overtemperature condition, triggering a protection control shutdown. The system is designed to stop compressor operation before heat-related damage can occur. This code points to an issue with heat rejection in the outdoor unit, the refrigerant charge level, or possibly the sensor itself.

No. The E402 code triggers a protection shutdown specifically to prevent compressor damage from excessive heat. Bypassing or repeatedly resetting the unit without addressing the root cause risks permanent compressor failure, which is a much more costly repair. The system should remain off until the underlying issue is diagnosed and corrected.

Repair costs depend heavily on the root cause. Cleaning the condenser coil or clearing airflow obstructions may involve only a service call fee, typically in the range of $75 to $150. Refrigerant recharge can cost $150 to $400 or more depending on refrigerant type and the amount needed. Condenser fan motor replacement generally runs $150 to $350 in parts and labor, while a full compressor replacement can range from $600 to $1,500 or higher depending on the unit.

Some basic checks are within reach for a homeowner, such as clearing debris from around the outdoor unit, cleaning a visibly dirty condenser coil, and ensuring nothing is blocking airflow. However, diagnosing low refrigerant, testing the discharge temperature sensor, or inspecting the condenser fan motor properly requires tools and training. A licensed HVAC technician should be called if basic clearing steps do not resolve the error.

A power reset may temporarily clear the error and allow the unit to restart, but if the underlying cause is not fixed, the E402 code will return, often quickly. Repeated high-temperature events can shorten compressor life significantly. A reset should only be used as part of a diagnostic process, not as a long-term solution.