LG Heat Pump Error Code P723

P723 indicates the compressor has been shut down by the low pressure sensor protection control at stage 3. The system detected that refrigerant pressure on the suction side dropped below a safe operating threshold. This is a protective lockout designed to prevent compressor damage from running under low pressure conditions. A refrigerant gauge check is the recommended first step to determine whether the issue is a true pressure problem or a sensor fault.

No, you should not attempt to override or continuously reset the unit while P723 is active. The code represents a compressor protection shutdown, and continued operation under low pressure conditions can cause severe mechanical damage to the compressor. Leave the unit off and contact a technician to diagnose the underlying cause before resuming normal operation.

Repair costs vary significantly depending on the cause. A refrigerant recharge after locating and fixing a leak can range from a few hundred dollars to over a thousand dollars depending on refrigerant type and the extent of the leak repair. Replacement of an expansion valve or filter drier typically falls in the range of a few hundred to several hundred dollars in parts and labor. Sensor replacement is generally a lower-cost repair, while compressor replacement if damage has already occurred can cost well over a thousand dollars.

Some basic checks like inspecting for blocked airflow, cleaning coils, or checking that air filters are clear can be done without special tools. However, diagnosing and correcting refrigerant charge issues, expansion valve faults, or sensor replacements requires refrigerant handling certification and professional equipment. Most repairs that actually resolve P723 will require a licensed HVAC technician.

A reset may temporarily clear the code and allow the system to restart, but if the underlying cause is not corrected the error will return, often escalating back to the stage 3 lockout quickly. Because P723 is a stage-based protection sequence, repeated resets without repair can lead to a harder lockout or compressor damage. Resetting is not a substitute for diagnosing the root cause.