Numerous types of solar water heater are used throughout the world. These heaters can be classified into two groups as pumped systems and thermo siphon systems. However, water temperature cannot be controlled by these systems. In this study, a new temperature-controlled parabolic trough collector (TCPTC) was designed and analyzed experimentally. The analysis was made at a temperature range of 40-100 degrees C, with at intervals of 10 degrees C. A detailed analysis was performed by calculating energy efficiencies, exergy efficiencies, water temperatures and water amounts. The highest energy efficiency of TCPTC was calculated as 61.2 for 100 degrees C. As the set temperature increased, the energy efficiency increased as well. The highest exergy efficiency was calculated as 63 for 70 degrees C. However, as the set temperature increased, the exergy efficiency did not increase. Optimum exergy efficiency was obtained for 70 degrees C. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.