LG Air Conditioner Error Code 47

Error code 47 indicates a fault with the constant speed compressor discharge pipe temperature sensor. The control board has detected that the sensor's resistance reading is either above 5 MΩ, which signals an open circuit, or below 2 kΩ, which signals a short circuit. Both conditions are outside the acceptable measurement range, so the system stops operation to protect the compressor. The root cause is typically a failed sensor, a damaged wire, or a loose connector.

No, you should not attempt to bypass or continue running the unit with this error active. The discharge pipe temperature sensor is a key protection input for the compressor. Without a reliable temperature reading, the control board cannot detect an overheating condition, which could result in compressor damage. Leave the unit off until the fault is diagnosed and corrected.

A power reset may temporarily clear the error code from the display, but the fault will return as soon as the control board re-reads the sensor and detects the out-of-range resistance value. Error code 47 reflects a hardware condition that requires physical inspection and repair of the sensor, wiring, or PCB. Resetting without correcting the underlying fault does not resolve the problem.

Some steps are accessible to a knowledgeable DIYer. You can inspect and reseat the sensor connector at the PCB and check for visible wiring damage without specialized tools. Measuring sensor resistance requires a digital multimeter and knowing where the discharge pipe thermistor is located in the outdoor unit. However, if the sensor or PCB needs replacement, and especially if refrigerant handling is involved for any related repairs, a licensed HVAC technician should complete the work.

If only the discharge thermistor needs replacement, parts typically cost in the range of $15 to $60 depending on the model, with labor adding $75 to $150 or more depending on your location and the service provider. If the control PCB is the failed component, parts alone can range from $100 to $350 or higher, which significantly increases the total repair cost. Getting a diagnostic quote before authorizing parts replacement is recommended.