Samsung Heat Pump Error Code E105

E105 indicates an open or short circuit fault in the discharge temperature sensor for the fixed-speed compressor (compressor 3). The control board has detected that the sensor signal is outside the valid range, meaning the sensor, its wiring, or its connector has failed electrically. The system logs this code to prevent operation without reliable compressor temperature monitoring.

Running the system with an active E105 fault is not recommended. The discharge temperature sensor is a critical protection input for compressor 3, and operating without reliable temperature feedback risks compressor overheating and permanent damage. The system may already be preventing operation as a safety measure. Address the fault before resuming normal use.

A power reset may temporarily clear the E105 code if the fault was caused by a momentary connection issue, but the code will return if the underlying electrical fault in the sensor circuit has not been resolved. Repeatedly resetting without diagnosing the root cause will not fix the problem and could delay necessary repairs. Confirm the sensor, wiring, and connector are all functioning correctly before relying on a reset to clear the fault.

A knowledgeable DIYer can inspect and reseat the sensor connector, check for visible wiring damage, and measure thermistor resistance with a multimeter. However, if the sensor or PCB needs replacement, or if the unit uses refrigerants requiring certification to handle, a licensed technician should complete the repair. Working inside the outdoor unit involves line voltage components that present a shock hazard if proper precautions are not taken.

Repair costs vary depending on the root cause. If only the connector needs cleaning or reseating, the cost may be limited to a service call fee, typically in the range of $75 to $150. Replacing the discharge temperature sensor usually adds $20 to $80 in parts. If the main PCB requires replacement, costs can range from $300 to $700 or more including labor.