E31

Unit Address Duplication / Outdoor Unit Address Error

Mitsubishi Electric · R410A Systems

What does E31 mean?

An indoor unit has a duplicated address number (within the range U00-U47), or there is an incorrect address setting for the outdoor unit. This leads to communication conflicts and prevents proper system control.

Common Causes

  • Duplicate unit addresses detected on the control network.
  • Outdoor unit's address setting is incorrect or duplicated.
  • Conflict with a newly added unit's address.
  • Re-addressing process failed to resolve conflicts.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Review and verify the DIP switch or parameter settings for the address of each indoor unit, ensuring all are unique within the U00-U47 range.

  2. 2

    Check the outdoor unit's address settings to ensure it is configured correctly and not conflicting with indoor unit addresses.

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Verified technical data. Last updated: March 2026

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Source: Mitsubishi Electric R410A Systems