LG Heat Pump Error Code E310

E310 indicates an OPEN or SHORT fault detected on the discharge temperature sensor for fixed capacity compressor 3. The control board measures the sensor's output voltage and triggers this error when the reading goes above 4.95V (indicating a temperature below -30°C) or below 0.5V (indicating a temperature above 151°C). This fault detection is only active when the outdoor temperature is above -10°C. The system flags this error to protect the compressor from operating without valid discharge temperature data.

It is not advisable to continue operating the system with an active E310 error. The discharge temperature sensor is a key safety input that protects the compressor from overheating. Without a valid sensor reading, the control board cannot detect a dangerously high discharge condition, which could result in compressor damage. Leave the system off until the fault is diagnosed and resolved.

A power reset may temporarily clear the E310 error code and allow the unit to restart, but the error will return if the underlying fault in the sensor circuit is still present. Because this error relates to a hardware failure in the sensor, wiring, or board, a reset does not address the root cause. Repeated resets without repair can mask a developing problem and risk compressor damage.

Some basic checks are within reach for a knowledgeable DIYer, such as inspecting the sensor wiring for visible damage and verifying that the sensor connector is fully seated and free of corrosion. However, diagnosing an OPEN or SHORT condition accurately requires a multimeter to measure sensor resistance and circuit continuity. Replacing the discharge sensor or the outdoor control board involves working inside the outdoor unit and should be performed by a qualified technician familiar with refrigerant systems and high-voltage components.

Repair costs depend on the root cause. Replacing a discharge temperature sensor typically falls in the range of $100 to $300 including parts and labor. If the issue is a wiring repair or connector cleaning, costs may be lower, generally $75 to $200 for a service call and labor. If the outdoor control board requires replacement, costs can range from $400 to $900 or more depending on the unit model and parts availability.