Remote controller transmission error (Main/Sub controller to Indoor unit)

What does E0 mean?

The main or sub remote controller cannot receive normal transmission from the indoor unit (refrigerant address '0') for 3 minutes, or a sub-remote controller loses signal for 3 minutes (E0). This signals a communication failure from the indoor unit to the remote controller, often due to wiring issues, misconfiguration (all sub-controllers), or a faulty transmitting/receiving circuit. This prevents the user from monitoring or controlling the system.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Verify remote controller wiring specifications, including total length (max. 500m) and number of connected units (max. 16 units, max. 2 controllers).

2. 4

   Perform a remote controller diagnosis. If 'RC NG' appears, replace the remote controller. If 'RC OK' but the error persists, replace the indoor controller board.

3. 5

   If 'RC E3' or 'ERC 00-06' is displayed, investigate and address potential noise interference on the transmission wire.