F3 (4 LED flashes) - Communication fault between IPM and outdoor PCB

What does F3 mean?

The outdoor unit's LED1 flashes four times, signaling a communication problem between the Intelligent Power Module (IPM) and the main Outdoor Printed Circuit Board (PCB).

• Loose wiring connection between IPM and PCB
• Faulty IPM module
• Faulty outdoor PCB
• Damaged communication line

Click steps to track your progress.

1. 1

   Turn off the AC unit at the main power supply for at least 10 minutes, then restart it.

2. 2

   Ensure there are no obvious external interferences near the outdoor unit.

3. 3

   If the issue persists, contact a qualified technician to inspect the internal connections and components.