EF — Connecting excessive number of units and branch boxes

What does EF mean?

This error indicates that the system has detected more indoor units or branch boxes connected than the outdoor unit is designed to support. This prevents the system from operating due to exceeding its capacity limit.

• Exceeded the maximum number of connectable indoor units for the outdoor model.
• Too many branch boxes connected to the system.
• Incorrect system configuration or wiring errors.

Click steps to track your progress.

1. 1

   Refer to the outdoor unit's specifications in the installation manual to determine the maximum allowed number of indoor units and branch boxes.

2. 2

   Carefully count and verify the actual number of connected indoor units and branch boxes.

3. 3

   If the number exceeds the allowed limit, disconnect the excess units or branch boxes, then restart the system.

4. 4

   Ensure that no unauthorized units or branch boxes have been inadvertently added to the system.

5. 5

   If the actual number of units is within limits, a technician should check the control wiring and configuration.