Outdoor Board LED1 (green) blinks three times and LED2 (red) blinks one time alternately - Serial communication error (between outdoor controller board and outdoor power board)

What does A0-A8 mean?

During startup or operation, the outdoor unit's LED1 (green) blinks three times and LED2 (red) blinks one time alternately, indicating a serial communication error between the outdoor controller board and the outdoor power board.

• Connector (CN4) on outdoor controller board and outdoor power board is disconnected or poorly connected.
• Poor connection of connectors on outdoor controller board (CNMNT and CNVMNT).

Click steps to track your progress.

1. 1

   Check if connector (CN4) on the outdoor controller board and outdoor power board is not disconnected.

2. 2

   Check if there is poor connection of connectors on the outdoor controller board (CNMNT and CNVMNT).

3. 3

   Re-check the error by turning off the main power, waiting, and turning it back on.