Error Code: EL 16 – Communication Malfunction Between Adapter Board and Outdoor Main Board

Error Code: EL 16 – Communication Malfunction Between Adapter Board and Outdoor Main Board

What this means:
The adapter PCB cannot detect the outdoor main control board. This usually indicates a wiring fault, board failure, or poor connection between the adapter and main PCBTS40.

Try this first (quick reset):

1. Turn off power to the system.

2. Wait at least 3 minutes.

3. Restart the unit and observe if the error clears.

• If the error clears — the system is operating normally.

• If the error returns — proceed with the following diagnostics.

Next steps (for technicians):

1. Check the wiring and connections:

   • Ensure all connection wires between the adapter board and outdoor main PCB are secure and properly inserted.

2. Are all connections good?

   • If NO → fix or replace the connection wires.

   • If YES → continue.

3. Replace the adapter PCB

   • If communication is still not restored → replace the adapter board.

4. If issue persists after adapter replacement:

   • Replace the outdoor main PCB.

What you might need:

• Connection wires

• Adapter PCB

• Outdoor main PCB

Helpful tip:
Most EL 16 issues stem from poor or reversed wiring. Always check physical connections before replacing boards.

Click here to view the detailed guide.TS40