E404 (Red ON, Green Blink, Yellow OFF) — Outdoor overload protection when compressor stops

What does E404 mean?

The outdoor unit's PCB LED displays E404 when its overload protection activates, causing the compressor to stop. This indicates a potential issue with the compressor or the system's ability to handle the load.

• Compressor fault during startup
• Electrical overload condition
• Restricted airflow or refrigerant issues (leading to high pressure)

Click steps to track your progress.

1. 1

   Turn off the main power to the outdoor unit at the circuit breaker.

2. 2

   Wait for at least 10-15 minutes to allow the system to cool down and reset.

3. 3

   Restore power and attempt to restart the air conditioning system.

4. 4

   If the error persists or reoccurs frequently, contact a qualified technician to inspect the compressor and system pressures.