LG Air Conditioner Error Code CH47

CH47 on an LG air conditioner indicates an open or short circuit fault in the constant-speed compressor discharge pipe thermistor. This sensor monitors the temperature of the refrigerant leaving the constant-speed compressor. When the control board detects a signal outside the valid resistance range, it stores CH47 and shuts down the system to prevent operation without accurate discharge temperature data.

No, you should not continue running the unit while CH47 is active. The discharge pipe thermistor is a protective sensor, and without accurate temperature readings from it, the control system cannot detect overheating conditions at the constant-speed compressor. Continued operation could risk compressor damage. The system will typically disable itself when this fault is detected.

A power reset may temporarily clear the CH47 code, but the error will return if the underlying fault in the thermistor circuit has not been corrected. If the thermistor is truly open or shorted, or if wiring is damaged, the control board will detect the out-of-range signal again as soon as it attempts to read the sensor. A reset is only a lasting fix if the cause was a momentary glitch, which is uncommon with this particular code.

A knowledgeable DIYer can inspect the thermistor wiring and connectors for visible damage, corrosion, or loose connections, and potentially reseat connectors to resolve the fault. However, testing thermistor resistance requires a multimeter and knowledge of expected NTC resistance values at specific temperatures. Replacing the thermistor or control board involves working near refrigerant lines and electrical components, so those steps are generally best handled by a certified technician.

If the thermistor sensor is the faulty component, repair costs are generally in the range of $75 to $200 including parts and labor, as thermistors are relatively inexpensive sensors. If the wiring harness or control board requires replacement, costs can rise to the range of $150 to $600 or more depending on the specific board and labor rates in your area. Getting a diagnostic visit from a technician will help pinpoint the exact failed component before committing to parts costs.