LG Heat Pump Error Code CH44

CH44 indicates a problem with the ambient temperature sensor on the outdoor unit of your LG heat pump. This NTC thermistor tells the system the outdoor air temperature, which the control board uses to manage defrost cycles and compressor operation. The fault triggers when the sensor signal falls outside expected parameters. Diagnosis involves checking the connector and measuring resistance (10k ohm at 25 degrees Celsius unplugged) or voltage (2.5Vdc at 25 degrees Celsius plugged in).

Operating the unit with an active CH44 fault is not recommended. Without an accurate ambient temperature reading, the control board cannot properly manage defrost cycles or compressor protection logic, which can lead to equipment damage over time. The system may also limit its own operation automatically when this fault is present. Addressing the fault before continued use is the safest approach.

If only the connector needs reseating or cleaning, the repair cost may be limited to a service call fee, typically in the range of $75 to $150. Replacing the ambient temperature sensor itself is generally an inexpensive part, with sensor costs often ranging from $20 to $60 plus labor. If the outdoor control board is the root cause, board replacement can range from $200 to $600 or more depending on the model, plus labor.

A knowledgeable DIYer can inspect and reseat the sensor connector and visually check the wiring harness for damage without special tools. Testing the sensor resistance with a multimeter is also straightforward if you are comfortable working with electrical components. However, if the sensor itself needs replacement or the outdoor PCB is suspect, comfort with disassembling the outdoor unit and handling refrigerant-adjacent components is required. When in doubt, a certified HVAC technician should complete the repair.

A power reset may temporarily clear the CH44 code, but if the underlying sensor fault still exists, the error will return once the system restarts and the control board re-evaluates the sensor signal. A reset alone is not a fix. The sensor connector, wiring, and sensor resistance all need to be verified before the fault can be considered resolved.