India is blessed with abundant solar energy. Solar water heater system is a technically proven successful application for use of this energy. However the market for the solar water heater is not yet developed fully. This informative hand book on solar water heater is prepared, for the Ministry of New and Renewable Energy (MNRE), to address the concerns of solar water heater system users for different solar water heating applications. The objective of the hand book is to help users make the right and informed decision while purchasing solar water heater. This hand book also intends to develop a better understanding of the solar water heating systems and to provide basic guidance for periodic maintenance and trouble shooting mechanisms for a reliable and durable service from the solar water heater.