Samsung Heat Pump Error Code E487

E487 indicates a breakaway or loss-of-signal fault with the discharge temperature sensor on the fixed compressor, referred to as compressor 3. The control board cannot read a valid temperature from the sensor monitoring refrigerant gas leaving that compressor. This is typically caused by the sensor coming loose from its holder, a failed sensor, or a wiring problem.

Running the system with E487 active is not recommended. The discharge temperature sensor protects the compressor from overheating by allowing the control system to monitor operating conditions. Without reliable sensor data, the compressor could operate outside safe temperature limits and sustain damage. Leave the unit off until the fault is diagnosed and resolved.

A reset may temporarily clear the fault code, but E487 will return if the underlying issue has not been corrected. The control board monitors the sensor continuously, and any open circuit or out-of-range reading will trigger the code again during operation. A permanent resolution requires inspecting, measuring, and if necessary replacing the sensor or repairing the wiring before the reset will hold.

Start by checking that the discharge temperature sensor is properly seated in its mounting holder on the compressor discharge line. If the sensor is secure, use a multimeter to measure its resistance and verify the reading is consistent with the surrounding temperature. If the sensor reads open circuit or the value is clearly incorrect, the sensor will need to be replaced. Also inspect the wiring harness and connectors between the sensor and the control board for damage or corrosion.

If the fix is simply reattaching a loose sensor, repair costs may be limited to a service call fee, typically in the range of $75 to $150. If the discharge temperature sensor itself needs replacement, parts and labor together generally fall in the range of $150 to $400 depending on the technician and region. Control board replacement, if needed, is the most expensive scenario and can range from $300 to $700 or more.