M-NET NO RESPONSE

What does A8 (6608) mean?

This abnormality is detected if a message was transmitted, an acknowledgment (ACK) of receipt was received, but no response command returns. The transmitting side detects this abnormality every 10 seconds, 6 times continuously. The remote controller displays the address and attribute of the controller that did not reply (ACK).

• M-NET communication bus failure.
• Outdoor unit not responding to M-NET commands.
• Loose or damaged M-NET wiring.
• Incorrect M-NET address setting.
• Controller unit failure.

Click steps to track your progress.

1. 1

   Check the transmission waveform and inspect for noise on the transmission wire.

2. 2

   Turn off the power supply of the outdoor unit, indoor unit, FRESH MASTER, or LOSSNAY simultaneously for 5 minutes or more, then turn the power on again. This may reset an accidental malfunction.

3. 3

   If the abnormality (A8) regenerates after a power cycle, the controller at the displayed address and attribute may be defective and require replacement.

4. 4

   Verify that the total transmission wire length does not exceed 1000m (656ft) and the remote controller line does not exceed 15m (49ft), as over-range extension can affect voltage and signal.

5. 5

   Confirm that the transmission wire type matches the specifications: With shield wire (CVVS, CPEVS) or With normal wire (no shield - VCTF, VCTFK, CVV, CVS, VVR, VVF, VCT) with a diameter of 1.25mm² [AWG16] or more.