Error 11 warns about a communications failure between the Airzone AC unit gateway and the indoor unit. The system loses communication with the AC unit and will therefore open all its zones and disable control from the system's thermostats, thus allowing the AC unit to operate from the manufacturer's thermostat.

First check that the air conditioning unit has power. Check that the AC unit's thermostat is switched on. If not, switch on the air conditioning unit and the error will disappear after about a minute.

If the problem persists, check whether the AC unit operates properly independently of the system. To do so, disconnect the AC unit from the Airzone system and activate the unit from the AC unit's thermostat. If the AC unit does not operate independently of the Airzone system, get in touch with its manufacturer.

If the AC unit operates properly, continue with the checks to be found at: ( My thermostat displays Error 9 ).