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A8

A8 - 2 red flashes, 5 green flashes — M-Net no response

Mitsubishi Electric · Air Conditioning

What does A8 mean?

This fault indicates that the M-Net system is not responding. Check wiring, ensure the transmission range is not exceeded, and verify the M-Net converter and wiring type.

Common Causes

  • M-Net system not responding
  • Faulty A-M-Net wiring
  • Transmission wiring range exceeded
  • Faulty A-M-Net converter or incorrect wiring type

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Inspect the A-M-Net wiring for proper connection and integrity.

  2. 2

    Confirm that the transmission wiring length does not exceed the maximum allowed.

  3. 3

    Check the A-M-Net converter for faults.

  4. 4

    Ensure the correct type of wire is used for the M-Net connection.

Browse all codes in this manual (170)
Verified technical data. Last updated: April 2026

Related Faults

0.5-second ON / 0.5-second OFF blinkUpper lamp blinks 0.5-second ON/OFF - Miswiring or serial signal error00Normal operation - No error codes1 beep during error display mode1 beep during error display mode - Unit has an error (different code)
Source: Mitsubishi Electric Air Conditioning
Open Manual (Page 16)Search more codes in this manual