LG Heat Pump Error Code E122

E122 indicates an indoor unit Electronic Expansion Valve (EEV) close failure. The indoor PCB commanded the EEV to close but did not detect a successful response from the valve. This causes the system to shut down to prevent refrigerant flow issues that could harm the compressor.

No. E122 causes the system to stop operation as a protective measure. Attempting to bypass this shutdown and continue running the unit without correcting the EEV fault could result in improper refrigerant flow, reduced efficiency, or damage to the compressor. The system should remain off until the fault is diagnosed and resolved.

Repair costs vary depending on the root cause. If only a wire reconnection or coil reseating is needed, you may only pay for a service call, typically in the range of $75 to $150. If the EEV coil or valve assembly requires replacement, parts and labor combined can range from $150 to $450 or more. An indoor PCB replacement represents the higher end of potential costs.

The first step is to press the K3 reset key on the indoor unit to clear the fault. You can also visually inspect the EEV wire harness for loose connections and confirm the EEV coil is fully seated on the valve body. However, if the error returns after reset, further diagnosis involving electrical testing of the coil and PCB output requires a qualified technician.

Pressing the K3 reset key may clear the code if the fault was caused by a transient electrical issue or a brief coil seating problem. However, if the underlying cause such as a failed coil, damaged wiring, or faulty valve body is still present, the E122 code will return. A reset is the correct first step but is not a permanent fix if a component has failed.