F3 - Communication Fault Between IPM and Outdoor PCB

What does F3 / LED1 flash 4 times mean?

The outdoor unit's LED1 flashes 4 times, indicating a communication problem between the IPM module and the outdoor PCB. This suggests a wiring issue or a fault in one of these components.

• Outdoor PCB is broken
• IPM module is broken
• Communication wiring is disconnected or loose

Click steps to track your progress.

1. 1

   Turn off the main power switch to the air conditioner before checking connections.

2. 2

   Ensure that the CN23 and CN24 terminals on the outdoor PCB are tightly connected.

3. 3

   Verify that the CN10 and CN11 terminals on the IPM module are tightly connected.

4. 4

   Check that the connection between the power module and the outdoor P&N line is secure.

5. 5

   Turn the power back on and restart the unit. If the fault persists, contact a qualified technician.