ACiQ PTAC Error Code E4

Communication Malfunction Between Display Board and Control Board

There is a communication error between the unit's display board and control board.

Error at Start Up or During Normal Operation

  • Check the wire between the display board and the control board and ensure that no wires have come loose.
  • Disconnect the unit from power for 5 minutes, and then start the unit back up.
  • If the problem persists, reach out to the manufacturer for additional troubleshooting or part replacement.