LG Heat Pump Error Code P803

P803 indicates an Electronic Expansion Valve (EEV) opening error in the indoor unit of the LG heat pump. The EEV is a stepper motor driven valve that regulates refrigerant flow into the indoor coil, and this code means the valve is not reaching its commanded opening position. LG classifies this as a low-level risk error, so the indoor unit continues to operate normally while the fault is active.

P803 is rated as a low-level risk fault by LG, and the indoor unit continues to operate normally when this code is active. It is not an immediate safety hazard. However, leaving an EEV fault unresolved can eventually affect system efficiency and refrigerant flow balance, so scheduling a service call in the near term is advisable.

A power reset may temporarily clear the P803 code from the display, but if the underlying EEV fault persists, the error will return during operation. A reset is useful as an initial step to determine whether the fault is intermittent, but it does not repair a failed stepper motor, damaged wiring, or stuck valve body. Persistent reappearance of P803 after a reset confirms a component issue that requires hands-on diagnosis.

Some basic checks, such as inspecting wiring connectors for looseness or corrosion and reseating them, are within reach of a knowledgeable DIYer. However, testing stepper motor coil resistance, diagnosing control board outputs, and replacing the EEV assembly typically require technical knowledge and proper tools. Any work involving refrigerant handling must be performed by a certified HVAC technician.

Repair costs depend on the root cause. If only a connector needs reseating, the cost may be limited to a service call fee, typically in the range of $75 to $150. If the EEV stepper motor or full valve assembly requires replacement, total costs including parts and labor generally range from $200 to $600 or more depending on the model and local labor rates.