LG Air Conditioner Error Code 211

Error code 211 on an LG air conditioner indicates a problem with the HR unit 3 sub-cooling discharge pipe temperature sensor. The system has detected either an open circuit or a short circuit in that sensor or its lead cable. This prevents the control board from receiving valid temperature data from that part of the refrigerant circuit, causing the unit to flag the fault and interrupt normal operation.

Running the system with error code 211 active is not recommended. Without a functioning sub-cooling discharge pipe temperature sensor, the control board cannot properly manage refrigerant flow in that circuit, which could lead to inefficient operation or potential system damage. It is best to shut the unit down and have the fault diagnosed before resuming normal use.

A power reset may temporarily clear the error code from the display, but the fault will return if the underlying cause has not been addressed. Because error code 211 indicates a hardware fault in the sensor circuit, the sensor connection, wiring, or sensor itself must be inspected and repaired before the system will operate reliably without the code reappearing.

Some basic checks, such as verifying that the sensor connector is fully seated and inspecting the lead cable for visible damage, can be performed without specialized tools. However, testing the thermistor resistance and tracing wiring faults within the HR unit typically requires a multimeter and familiarity with refrigerant system components. Replacement of the sensor or wiring harness is best handled by a qualified HVAC technician.

Repair costs depend on whether the issue is a loose connection, damaged wiring, or a failed sensor. A simple connector reseating or cleaning may involve only a service call fee, typically in the range of $75 to $150. If a replacement temperature sensor or wiring harness is needed, total costs including parts and labor could range from $150 to $400 or more depending on your location and system model.