LG Heat Pump Error Code P524

P524 indicates that the outdoor unit's Electronic Expansion Valve (EEV) failed a close position self-diagnostic check. The system tests the valve's ability to fully close as part of its startup or operational routine, and when the valve does not respond as expected, this code is generated. The heat pump will not operate normally until the fault is resolved to prevent uncontrolled refrigerant flow and potential system damage.

Operating the heat pump while P524 is active is not recommended. The error indicates the refrigerant flow control valve may not be functioning correctly, which can lead to improper refrigerant distribution, compressor damage from liquid slugging, or reduced system efficiency. The unit may refuse to run in this state as a protective measure.

A power reset may temporarily clear the P524 code and allow the unit to attempt operation again, but if the underlying hardware fault persists, the error will return during the next self-diagnostic cycle. Resetting the unit is not a fix for a failed EEV motor, damaged wiring, or faulty control board. Persistent recurrence of P524 after resets confirms that a physical inspection and repair are needed.

Most of the repairs involved with P524 require handling refrigerant, which requires EPA Section 608 certification in the United States. Homeowners can visually inspect the outdoor unit wiring harness for obvious damage or loose connectors, but replacing the EEV or diagnosing the stepper motor coil requires proper tools and technical knowledge. It is strongly recommended to have a licensed HVAC technician perform the repair.

Repair costs vary depending on the root cause. EEV coil or assembly replacement typically ranges from $200 to $600 in parts and labor. If the outdoor control board is also at fault, costs can rise to $400 to $900 or more depending on the model and local labor rates. A diagnostic service call alone generally costs $75 to $150 before any repairs are made.