LG Air Conditioner Error Code 210

Error code 210 indicates a temperature sensor fault at the sub-cooling inlet pipe of HR unit 3. The system has detected either an open circuit or a short circuit condition in that sensor or its wiring. This prevents the control board from receiving valid temperature data for the sub-cooling circuit, which can limit or halt system operation.

Operating the system with an active error code 210 is not recommended. Without valid temperature data from the sub-cooling inlet sensor, the control system cannot properly regulate refrigerant flow through that circuit. Continued operation could lead to inefficient performance or potential damage to other components in the refrigerant system.

A power reset may temporarily clear the code from the display, but if the underlying fault in the sensor or its wiring is still present, the code will return once the system restarts and checks the sensor circuit again. A reset alone does not resolve the problem. The sensor connection and wiring must be inspected and repaired to permanently clear the error.

Some steps are accessible to a knowledgeable DIYer, such as visually inspecting the sensor connector and lead cable for obvious damage, loose connections, or corrosion. However, accessing the internal components of an HR unit and properly testing sensor resistance values requires familiarity with refrigerant systems and electrical diagnostics. If the wiring inspection does not reveal a clear cause, a qualified HVAC technician should complete the diagnosis and any necessary repairs.

If the fix is simply reseating a loose connector, there may be no parts cost, only a service call fee which typically ranges from $75 to $150. If the sensor itself needs replacement, parts and labor together generally range from $150 to $400 depending on the unit and local labor rates. Cable harness replacements or more involved repairs could push costs higher.