Co-b4 — Communication loss with compressor B4 board

What does Co-b4 mean?

Communication has been lost with the control board for compressor B4. This could be due to a bus fault or a defective slave board. The compressor is shut down.

• Installation bus fault.
• Defective slave board for compressor B4.
• Loose wiring connection to the slave board.
• Interference on the communication bus.

Click steps to track your progress.

1. 1

   Check all wiring connections to the compressor B4 slave board.

2. 2

   Inspect the communication bus for damage or interference.

3. 3

   Attempt to reset the communication by cycling power to the unit.

4. 4

   If the issue persists, the slave board may need replacement.