It is a device that allows converting the solar energy or sunlight for water heating using a solar thermal collector (either flat panels or evacuated tubes). The heated water is stored in an insulated tank for further use whenever required. Water is heated directly or using light concentrating mirrors. There are types of solar water heater. These heaters are favourable of sun rays. Smallest size in this system is 100litres per day means it can preserve and deliver 100 litres of hot water in a day. This amount of water is normally sufficient for a family of 3-4 members. It completely saves the use of electricity or domestic gas which is the great benefit of these heaters. Water heater dealers are stocking these items in countable as it cost is high. For rough estimation, a 100 litres capacity of heater may cost approximately 20,000-22,000, depends on the type. There are two types of water heating systems. One is direct circulating system which works well in the rarely freezing climate and the other is indirect circulating system is friendly to freezing temperature.