Its main concept is converting electrical energy 2 heat enegry / chemical energy 2 heat has theheating elenment well insulated and closed in a metal tube .it is important not to let the element come in direct contact with water ,as,otherwise the latter will become live and dangerous. 
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Geysers work on a principle of converting electrical energy into the heat energy. There is heating element inside the geyser which gets heated. Cold water gets collected into the geyser tank and gets heated to a certain temperature. There is thermostat device, fitted in the geyser, which cuts off the electric supply to the geyser, once the water inside reaches a certain temperature. It helps conserving the electricity. For the convenience of the users, there are two LED lights are given on the below side of the geyser. Conventionally, these are red and green lights. When the element is heating up, red light is lighted and when the element stops working, green light starting emitting. Emission of green light means the water is hot at the maximum temperature allowed by the geyser. Cold water in the geyser come in through a separate inlet and hot water goes out through a separate outlet.
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