Indoor/Outdoor Unit Miswiring or Excessive Indoor Units

What does EC mean?

This communication error is detected when there is incorrect wiring of the indoor/outdoor connecting wire or if more than four indoor units are connected to the outdoor unit. This prevents proper communication and control between the indoor and outdoor units, leading to system malfunction.

• Miswiring of communication lines between indoor and outdoor units.
• More than the maximum allowable number of indoor units connected to the outdoor unit.
• Incorrect addressing of indoor units on the communication bus.
• Short circuit on the indoor/outdoor communication wiring.

Click steps to track your progress.

1. 1

   Verify the indoor/outdoor connecting wire terminations match the wiring diagram for correct connection.

2. 2

   Count the number of connected indoor units and confirm it does not exceed the maximum allowed limit of four units for this outdoor unit.

3. 3

   Inspect the indoor/outdoor connecting wire and power supply for signs of electrical noise interference.

4. 4

   Cycle power to the unit (turn off, then on again) to re-check for the error.