Rapid, easy and reliable human access to domestic hot water is one of the basic requirements in today's modern life. We need hot water for bathing, personal hygiene, washing clothes and dishes, and etc. Domestic hot water can be produced in different ways depending on the type of energy source used (electricity, gas, solar and other fuels) and the needs of the users. In our country, due to the low cost, natural gas is generally used to produce the required heat.