LG Heat Pump Error Code E314

E314 indicates a fault with the discharge temperature sensor on fixed capacity compressor 3. The control board has detected a sensor signal voltage either above 4.95V (open circuit, below -30°C equivalent) or below 0.5V (short circuit, above 151°C equivalent). This fault is only detected when the outdoor temperature is above -10°C. The system shuts down to prevent operating without accurate compressor discharge temperature monitoring.

No. The discharge temperature sensor is a critical safety input that protects the compressor from overheating. Running the unit without a functioning sensor means the system cannot detect dangerously high compressor discharge temperatures, which can cause permanent compressor damage. The unit should remain off until the fault is diagnosed and repaired.

Repair costs vary depending on the fault found. A replacement discharge temperature sensor typically costs between $20 and $80 for the part alone. If a control board replacement is required, parts can range from $150 to $500 or more. Adding labor from a certified HVAC technician, total repair costs generally fall between $100 and $700 depending on the specific cause and local service rates.

Basic checks such as inspecting and reseating the sensor connector are accessible to a knowledgeable DIYer. However, measuring sensor resistance accurately, tracing wiring faults, and replacing components inside an outdoor heat pump unit generally requires proper tools, refrigerant handling knowledge, and electrical safety training. A qualified HVAC technician is recommended for anything beyond connector inspection.

A reset may temporarily clear the fault code, but E314 will return if the underlying sensor or wiring fault has not been corrected. Because the fault is only detected when outdoor temperatures are above -10°C, the code may not reappear immediately after a reset in cold conditions. The sensor and wiring should be fully tested rather than relying on a reset as a fix.