E1 — Communication error between indoor and outdoor units (MMDB Indoor Units)

What does E1 mean?

For MMDB indoor units: This error means the indoor and outdoor units cannot communicate. This prevents the system from operating correctly.

• Damaged or loose communication wiring
• Faulty communication module on either unit
• Signal interference

Click steps to track your progress.

1. 1

   Inspect the communication wiring for damage or loose connections at both the indoor and outdoor units.

2. 2

   Ensure the wiring is properly terminated.

3. 3

   Consider potential sources of interference affecting the signal.

4. 4

   Perform a power cycle by turning off the main power for 30 seconds, then restoring it.