Samsung Air Conditioner Error Code P429

P429 indicates an outdoor unit compression rate 2 error, meaning the system has detected that the compressor is not maintaining the correct pressure ratio between the suction and discharge sides of the refrigerant circuit. This is a protective fault that shuts down the unit to prevent compressor damage. It typically points to a refrigerant issue, compressor wear, or an airflow problem at the outdoor unit.

No. The P429 fault is a protective shutdown triggered because the compressor is operating outside safe parameters. Continuing to run the unit in this state can accelerate compressor wear or cause permanent damage to the compressor. The system should remain off until the fault is properly diagnosed and repaired.

Repair costs vary widely depending on the root cause. A refrigerant recharge after fixing a leak can range from a few hundred dollars to over a thousand dollars depending on the refrigerant type and leak location. Condenser coil cleaning is relatively inexpensive, typically in the range of $75 to $200. Compressor replacement is the most expensive scenario, often falling in the range of $800 to $2,500 or more depending on the unit size and labor involved.

Most causes of P429 require professional diagnosis and repair. Checking and cleaning the outdoor condenser coil is one task a homeowner can safely perform, but anything involving refrigerant handling, compressor testing, or electrical component replacement must be done by a licensed HVAC technician. Attempting refrigerant work without certification is both illegal and dangerous.

A power reset may temporarily clear the error code and allow the unit to restart, but if the underlying problem is not resolved, the fault will return. In many cases, the unit will fault again quickly once it attempts to run under the same conditions. A reset is not a repair and should not be relied upon as a solution for P429.