LG Heat Pump Error Code E224

E224 indicates an open or short circuit fault in the COND-OUT SUB 1 temperature sensor, which monitors the condenser outlet temperature. The control board detected that the sensor signal is outside its expected resistance range, suggesting a wiring fault, disconnected connector, or failed thermistor. The system may limit operation or shut down to protect components until the fault is resolved.

Operating the heat pump with an active E224 fault is not recommended. The condenser outlet temperature sensor plays a role in regulating system performance and defrost cycles. Running without accurate sensor data could reduce efficiency, cause improper operation, or potentially contribute to component stress over time.

A power reset may temporarily clear the E224 code, but if the underlying fault, such as a failed sensor, damaged wire, or corroded connector, is still present, the error will return once the system reinitializes and re-reads the sensor signal. A reset is useful for confirming whether a fault is intermittent, but it is not a substitute for diagnosing and correcting the root cause.

A knowledgeable DIYer can check for loose or corroded connectors at the sensor and control board without specialized tools. However, measuring thermistor resistance and tracing wiring faults inside the unit requires comfort working around electrical components and refrigerant-side hardware. If the thermistor or control board needs replacement, a licensed HVAC technician is recommended.

Repair costs vary depending on the cause. Cleaning or reseating a connector may involve only a service call fee, typically in the range of $75 to $150. Replacing the NTC thermistor sensor usually costs between $100 and $250 including parts and labor. If the control board requires replacement, costs can range from $300 to $700 or more depending on the model and labor rates in your area.