Unit shows E5 and shuts down compressor shortly after starting; fan may continue to run.

Safety: Turn off power at the breaker. Overcurrent conditions can be dangerous; do not repeatedly reset and restart a tripping unit.

Steps:

• Check airflow: Ensure outdoor coil is clean and free of debris. Clean fins gently with a soft brush and low-pressure water, keeping water away from electrical components.
• Verify fan operation: Restore power briefly and observe if the outdoor fan starts and runs at full speed. If the fan is not running, shut power off and troubleshoot the fan motor and capacitor.
• Inspect wiring: With power off, check compressor and fan wiring for burnt connectors, loose terminals, or signs of arcing. Tighten or replace as needed.
• Compressor test (advanced): Using a multimeter, measure compressor winding resistance and check for continuity to ground. A short to ground or very low winding resistance indicates a failed compressor.
• Capacitor check: Inspect the run capacitor for bulging or leaks. Replace with the correct microfarad rating if suspect.
• PCB current sensor: If mechanical and electrical components test normal, the current-sensing circuit on the outdoor PCB may be faulty and require replacement.

When to call a technician: If the compressor is shorted or seized, or if you are not trained to test high-voltage components, contact a licensed HVAC technician. Compressor replacement and refrigerant handling require certification.