LG Air Conditioner Error Code 02

Error code 02 on an LG air conditioner indicates that the indoor unit inlet pipe temperature sensor has been detected as open-circuit or short-circuit by the PCB. This sensor is a thermistor that monitors refrigerant temperature at the heat exchanger inlet. The system stops normal operation when this fault is detected to prevent damage. The sensor, its wiring, and its connector at the PCB all need to be inspected.

The unit will typically stop operating when error code 02 is active, as the system uses the inlet pipe sensor to protect the heat exchanger from freezing and to control refrigerant flow. Attempting to bypass or ignore this error and force the unit to run could result in equipment damage. It is best to address the fault before resuming normal use.

Resetting the unit by cycling power may temporarily clear the error code, but the code will return if the underlying sensor fault has not been corrected. A reset does not repair a failed thermistor, a broken wire, or a disconnected connector. The error should be diagnosed and repaired properly before relying on the unit for normal operation.

A knowledgeable DIYer can check whether the sensor connector is properly seated at the PCB and inspect the wiring harness for visible damage without any special tools. Measuring sensor resistance requires a multimeter and basic familiarity with thermistor testing. However, if the sensor or PCB needs replacement, comfort with disassembling the indoor unit is required, and some regions require a licensed technician for any work involving refrigerant systems.

If the fix is simply reseating a loose connector, there may be no parts cost at all, though a service call fee will typically apply. Replacing the inlet pipe thermistor sensor is generally an inexpensive repair, with parts typically ranging from $15 to $60 depending on the model, plus labor. If the PCB itself needs replacement, costs can rise significantly, ranging from $150 to $400 or more for parts and labor.