E9 Error CodeUpdated 4 days ago

Introduction

The "E9" error code indicates smart controller communication error. This article is for Vertex Ducted Central Split (DYC-18) systems. 

The error code shows on the smart controller display. 

Troubleshooting

Cause: The communication between the smart controller and indoor control board is not functioning properly. 

• Check if the communication cable is plugged in tightly. Use a multimeter to measure if the 3-pin cable is broken. 
• Check if the DIP switch has selected the RS-485 communication mode. The SW1-1 of the indoor and outdoor units should be in the "On" position. 

  SW1-1	On	RS-485 communication mode
  	Off	24V control (factory default)

• Power and restart. If the fault is still the same, then replace the smart controller. 
• If replacing the smart controller does not solve the problem, then replace the indoor unit control board.