Samsung Heat Pump Error Code E552

E552 indicates that the indoor heat exchanger EVAP OUT sensor has separated from its mounted position on the evaporator outlet piping. This piping sensor monitors refrigerant temperature at the evaporator outlet, and physical detachment causes the control board to receive inaccurate readings. The system flags E552 to alert that the sensor is no longer in proper contact with the pipe.

Running the heat pump with E552 active is not recommended. Without accurate EVAP OUT temperature data, the system cannot properly regulate refrigerant flow or superheat, which can lead to inefficient operation, short-cycling, or potential stress on system components. It is best to address the sensor issue before resuming normal operation.

A simple power reset may temporarily clear E552 from the display, but the code will return if the underlying cause, sensor detachment or sensor failure, has not been corrected. The control board will re-detect the fault as soon as it reads an implausible temperature from the EVAP OUT sensor position. A permanent resolution requires physically inspecting, reseating, and securing the sensor before clearing the code.

If the sensor has simply come loose from the pipe, a knowledgeable DIYer who is comfortable opening the indoor unit can inspect the evaporator outlet area, reseat the sensor against the pipe, and secure the mounting clip. However, if the mounting hardware is damaged, the sensor wire is compromised, or the thermistor itself has failed, a qualified technician should handle the repair to ensure correct sensor placement and refrigerant system integrity.

If the sensor only needs to be reattached and the mounting clip is intact, repair costs are minimal and typically involve only a service call fee, which can range from around $75 to $150 depending on your location. If the sensor itself has failed and needs replacement, parts and labor together generally range from $100 to $300. Costs can be higher if the issue is discovered alongside other problems during the service visit.