Hot water boilers are mainly used for two purposes: heating and bathing. Hot water boiler through the hot water circulation pump circulating insulation tank of hot water, week after week to the tank of hot water heating, you can realize the purpose of bathing; hot water boiler through the hot water circulation pump circulating hot water heating pipeline through the radiators (radiators) can achieve the requirements of people's heating; hot water boiler and hot water circulation pump with the heat exchanger to achieve the dual function of bathing and heating.

Hot water boiler according to different fuels can be divided into electric hot water boiler, oil hot water boiler, gas hot water boiler, coal-fired hot water boiler, etc.; according to whether the pressure can be divided into atmospheric hot water boiler and pressurized hot water boiler two kinds of hot water boilers, we usually say that "hot water boiler" refers to atmospheric hot water boiler, because of its operational safety, people bath or heating Most of them adopt this kind of normal pressure hot water boiler.

Natural circulation of the hot water boiler, inlet and outlet water from the top of the upper cylinder take over, by the inlet distribution pipe will guide the inlet water into the down tube into the front and side of the lower combined box, through the water-cooled wall pipe heating rise. The front and rear ends of the upper drum are provided with water traps at the boundary between the falling and rising water streams, which only isolate the lower half of the drum cross-section. Forced circulation, the water into the front end of the lower box, from the front water-cooled wall tube up to the upper cylinder (this time the front water-cooled wall down tube canceled), and then transferred to the side water-cooled wall tube down tube to the side of the lower box, and then into the side water-cooled wall tube up to the upper cylinder, but also from the front convection tube bundle down to the lower cylinder, and finally in the upper and lower cylinder between the upper and lower cylinder and circuitous a few processes from the upper cylinder out of the back end of the water.