Samsung Heat Pump Error Code E484

E484 indicates that the sump temperature sensor for fixed compressor 3 has experienced a breakaway condition, meaning it has come loose from the compressor or become electrically disconnected. The sump sensor monitors temperature at the base of the compressor to protect it from liquid refrigerant pooling. The system stops normal operation when this fault is detected to prevent compressor damage. A physical inspection of the sensor and its wiring is the first step in diagnosing this fault.

No, you should not attempt to continue operating the heat pump while E484 is active. The sump temperature sensor is a protective component for the compressor, and running the compressor without valid sump temperature data removes an important safeguard against damage. Continued operation could result in compressor failure, which is a significantly more expensive repair.

If the repair involves only reattaching a loose sensor and reconnecting a harness, labor costs will be relatively low, typically in the range of $75 to $200 depending on your service provider and region. If the sensor itself needs replacement, parts costs can add $30 to $150 or more to that total. Costs rise significantly if wiring harness sections need to be replaced or if delayed diagnosis has led to secondary compressor damage.

A basic inspection to check whether the sensor connector is simply unplugged or the sensor has pulled free from its mount is something a knowledgeable DIYer can attempt. However, working on heat pump components involves high-voltage electrical circuits, so if you are not familiar with safely isolating power to the unit, a licensed technician should perform the repair. Any work involving the refrigerant circuit or internal compressor components must be handled by a certified technician.

A simple power reset will not permanently clear E484 if the underlying sensor disconnection or breakaway condition has not been corrected. The fault will return as soon as the control board checks the sensor circuit and finds no valid signal. The sensor must be physically reattached and the wiring confirmed to be intact before the error will clear and stay cleared.