LG Heat Pump Error Code Bx

The Bx error code indicates an electronic expansion valve open error on a specific indoor unit, where x represents that unit's address in the system. The fault is triggered when the stopped indoor unit's inlet or outlet temperature falls below 0°C during cooling mode, signaling that the EEV is not closing properly. The system halts operation to prevent coil icing and refrigerant circuit damage.

It is not advisable to continue operating the system with an active Bx error. The fault indicates that refrigerant is overflowing through a stopped indoor unit's coil, which can cause ice formation on the heat exchanger and potentially damage the refrigerant circuit or the indoor unit. The system is designed to shut down affected operation when this error occurs, and it should remain off until the underlying cause is resolved.

Repair costs vary depending on the cause. If the fix is simply reseating the EEV coil or reconnecting a loose wire, labor charges alone may apply, typically ranging from around $75 to $150 for a service visit. If the EEV coil requires replacement, parts and labor combined can range from $150 to $400. A failed indoor PCB or mechanical EEV valve replacement will be at the higher end, potentially $300 to $700 or more depending on the unit and parts availability.

Start by checking the EEV wiring connection at the indoor unit PCB and confirming the EEV coil is fully and correctly inserted on the valve body. Reseat any loose connectors or reposition the coil if needed, then press the reset key (K3) to clear the fault. If the error returns after resetting, the EEV coil or the indoor PCB may need to be tested and potentially replaced by a qualified technician.

Pressing the reset key (K3) can clear the Bx fault code after the underlying issue has been corrected. However, if the wiring connection or EEV coil problem has not been fixed, the error will return once the system attempts to operate again. A reset alone without addressing the root cause is only a temporary measure.