11. The automatic recirculating valve in the main condensate recirculating line is controlled by a temperature sensor which is located at the __________.

The temperature sensor is located at the air ejector condensate discharge to ensure the recirculating valve controls condensate temperature based on the air ejector condenser's outlet temperature, which directly impacts vacuum and ejector performance. Other locations provide inaccurate temperature readings and would not allow for effective control of the recirculation process.