Air cooled chillers have auxiliary heat recovery systems that include a heat recovery heat exchanger for transferring heat from a compressed refrigerant to a process fluid. According to certain embodiments, the air cooled chillers also includes a compressor, a condenser, an expansion device, and a controller to govern operations of the expansion device, a fan in the condenser, and other components of the chiller system. The controller may receive signals from temperature and pressure sensors located throughout the chiller system in order to determine a heat recovery load of the heat recovery heat exchanger. The controller may govern operations of the condenser fan and the expansion device according to a low heat recovery mode, an intermediate heat recovery mode, or a full heat recovery mode. In full heat recovery mode, the controller operates the expansion device based on subcooling detected in the heat recovery heat exchanger.