A7 (6607) - No ACK error (M-NET Remote controller)

What does A7 mean?

The M-NET remote controller for the Mitsubishi Electric PUMY Air Conditioner did not receive an acknowledgment (ACK) signal from another device on the network. This means a command was sent, but no confirmation was received. This applies only to M-NET remote controllers.

• Issue with the communication wiring (M-NET line)
• Faulty M-NET device that is not responding
• Device not powered on or not properly connected

Click steps to track your progress.

1. 1

   Note the error code displayed on the M-NET remote controller.

2. 2

   Power off the Mitsubishi Electric PUMY Air Conditioner system at the main electrical breaker.

3. 3

   Wait for at least 30 seconds, then restore power to the system.

4. 4

   If the error persists, contact a qualified service technician to check the M-NET communication line and all connected devices.