Samsung Air Conditioner Error Code E443

Samsung E443 is a high pressure fault that triggers when the refrigerant circuit's high-side pressure reads below expected levels prior to or during a cooling restart sequence. The system's PCB monitors the high pressure sensor continuously, and if the sensor reports a pressure value that falls beneath the acceptable threshold before cooling can be initiated, the unit locks out and raises E443 to prevent compressor damage. This lockout condition is specifically tied to the pre-cooling pressure check, meaning the system could not confirm adequate refrigerant pressure to safely restart the compressor.

Two primary failure modes produce this code. The first is a faulty or disconnected high pressure sensor. If the sensor's wiring harness has come loose from the PCB, corroded, or the sensor itself has failed internally, it can report an artificially low pressure signal that does not reflect actual system conditions. The second and more mechanically serious cause is actual refrigerant leakage. A leak reduces the total refrigerant charge in the system, causing a genuine drop in high-side pressure that the sensor correctly detects.

Diagnosing E443 requires a two-step approach. Technicians should first verify the high pressure sensor is firmly seated at its PCB connector and inspect the wiring for damage, corrosion, or pinching. If the connection is sound, a manifold gauge set should be connected to the high-side service port to measure actual system pressure. A reading significantly below the expected operating range for the refrigerant type confirms leakage, which requires leak detection, repair, and recharge before the system can be returned to service.