Samsung Air Conditioner Error Code 407

Error code 407 means the system detected high-side refrigerant pressure at or above 4.0 MPa (38 kg/cm2) and shut down the compressor as a safety precaution. This protection function prevents damage to the compressor and refrigerant circuit. The fault will remain active until the cause of elevated pressure is identified and corrected by a qualified technician.

No. Error 407 means the system has already shut down the compressor to prevent damage from excessive pressure. Attempting to bypass the fault or repeatedly resetting the unit without addressing the root cause risks compressor failure, refrigerant line rupture, or damage to other system components. Leave the unit off until a technician has diagnosed and repaired the problem.

Repair costs depend heavily on the root cause. If the fix is as simple as opening a closed service valve or clearing an airflow obstruction, a service call fee of roughly $75 to $150 may be all that is required. If a faulty EEV, failed fan motor, or damaged filter drier needs replacement, parts and labor can range from $200 to $600 or more depending on the specific component and system model. Refrigerant recovery and recharge adds additional cost if overcharge or a refrigerant-side restriction is involved.

Some initial checks are accessible to a knowledgeable DIYer, such as confirming the outdoor fan is running, checking for physical obstructions at the outdoor unit, and verifying service valves are fully open. However, diagnosing EEV operation, measuring system pressures with manifold gauges, and correcting refrigerant charge all require EPA Section 608 certification and specialized tools. Most of the root causes for code 407 require a licensed HVAC technician to resolve safely.

A power reset may temporarily clear the fault and allow the system to restart, but if the underlying cause of high pressure has not been corrected the unit will trip the same protection and log code 407 again, often within minutes of restarting. Repeatedly resetting the system under these conditions can accelerate compressor wear. A proper repair of the root cause is required for the fault to stay cleared.