If the dampers operate properly and LED D6 on the main control board turns on and off when zones are switched on and off, but the AC unit does not start up, proceed as follows:

Check that the AC unit's controller is connected to the Airzone communication gateway or to the air conditioning unit depending on the gateway model connected (Technical Data Sheet).

If the connection is correct according to your gateway's technical fact sheet, check whether the AC unit is operating properly. To do so, disconnect the system's communication gateway and check the AC unit using the manufacturer's thermostat.

If the AC unit does not operate when it is disconnected from the Airzone system, consult the AC unit's manufacturer.

If the AC unit starts up and shuts down when it is controlled from its own controller, reconnect the gateway to the AC unit's controls. Then check whether the system has detected the gateway. To do so, access the master thermostat's Information menu and check to see whether a gateway appears in the Devices menu.

If an AC unit gateway appears, the system is properly detecting the gateway and hence communications with the system are satisfactory. If, despite this, the AC unit still does not start up, check the wiring from the gateway to the AC unit.

Check your unit's compatibility with the Airzone AC unit gateway: Is my AC unit compatible with the Airzone system?

Check the self-diagnostic LED on your communication gateway with the AC unit (Technical Data Sheet).