E3

Remote controller transmission error

Mitsubishi Electric · PUZ-HA30/36NHA4 Outdoor Unit

What does E3 mean?

The remote controller cannot find a blank transmission path for 6 seconds, failing to send commands (E3). This can be caused by multiple 'main' remote controllers, connecting too many indoor units, duplicate refrigerant addresses, or issues with the remote controller's/indoor board's transmitting circuit. This prevents the user from controlling the system effectively.

Repair Steps

  1. 1

    Ensure only one remote controller is set as 'main' and others as 'sub' in a multi-controller setup.

  2. 2

    Verify that the remote controller is connected to only one indoor unit, unless in a correctly configured group control system.

  3. 3

    Check for unique refrigerant address settings across all units.

  4. 4

    Run a remote controller diagnostic (if available); if 'RC NG' is displayed, replace the remote controller. If 'RC OK' but the error persists, replace the indoor controller board.

  5. 5

    If 'RC E3' or 'ERC 00-66' is displayed, investigate and mitigate potential noise interference on the remote controller transmission wire.

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Verified technical data. Last updated: March 2026
Source: Mitsubishi Electric PUZ-HA30/36NHA4 Outdoor Unit