LG Air Conditioner Error Code E161

E161 indicates a mixed operation mode error on an LG heat pump system. It means the outdoor unit and one or more indoor units are attempting to operate in opposing modes at the same time, for example one unit calling for cooling while another calls for heating. The system shuts down to prevent damage because a heat pump refrigerant circuit can only move heat in one direction at a time. This error only appears on heat pump models.

A simple power reset may temporarily clear the error code, but it will return if the underlying mode conflict is not resolved. You must correct the mode settings on all indoor and outdoor units before restarting the system. If an automated controller or timer is sending conflicting commands, those settings must also be corrected to prevent the error from recurring.

If the cause is simply a mode setting conflict or user error, there is no parts cost and a technician service call may range from around 75 to 150 dollars depending on your area. If the fault is traced to a communication wiring issue, repair costs are generally low, typically in the range of 100 to 250 dollars for labor and any replacement wire or connectors. If a faulty indoor unit control board is identified as the cause, parts and labor combined can range from 200 to 500 dollars or more depending on the specific unit model.

Start by checking the operational mode set on the outdoor unit and on every connected indoor unit. Set all units to the same mode, either all cooling or all heating, and then restart the system. If you have a central controller or scheduling system, review any automated commands that may be sending conflicting mode signals to different units. If the error persists after confirming all modes match, inspect the communication wiring between the units for damage or loose connections.

The E161 error is not a safety hazard in the same way as refrigerant or electrical faults, but you should not attempt to force the system to run while the error is active. The system has halted operation specifically to protect the compressor and refrigerant circuit from the mechanical stress of operating under contradictory demands. Address the mode conflict before resuming normal use.