Energy saver of water heater

The invention provides an energy saver of a water heater. The energy saver is provided with a casing in cylindrical tower shape, the casing is provided with a thermal-insulating layer; a multilayer annular spring-like pipeline is installed in the casing, one end of the pipeline is connected with a water inlet, and the other end is connected with a water outlet; and the energy saver is installed on an air exhaust opening of the water heater. The energy saver of the water heater has simple structure and stable operation, is safe and reliable and can make the water temperature of the water heater to reach above 80 DEG C, thereby saving gas by about 20%-40% and maximally saving energy consumption and family economic expenditure; meanwhile, the energy saver of the water heater is easy to produce, popularize and utilize and is beneficial to energy conservation and emission reduction and green environmental protection advocated in China as well as economic benefits of the consumers.