6607 (A7) No ACK error - Controller of displayed address not recognized

What does 6607 (A7) mean?

This 'No ACK' error means the system cannot recognize the controller associated with a specific address. This typically happens if an address switch was changed while power was on, or if Fresh Master/Lossnay addresses were changed after synchronization.

• Previous address unit does not exist since the address switch was changed while in electric continuity status.
• Abnormality detected at transmitting from the indoor unit since the Fresh Master/Lossnay address are changed after synchronized setting by the remote controller.

Click steps to track your progress.

1. 1

   Turn off the power to the entire system at the main circuit breaker.

2. 2

   Verify that no address switches on any unit were changed while the system had power.

3. 3

   If Fresh Master or Lossnay units are present, confirm their addresses have not been changed after being synchronized by the remote controller.

4. 4

   Ensure all units requiring addresses are correctly set according to the installation manual.

5. 5

   Restore power. If the error persists, contact a qualified technician for further diagnosis.