Boilers, in general terms, are used for providing hot water for central heating or domestic hot water using. Water is heated by means of resistances in electric type boilers, and by burning gas in natural gas boilers. They can serve all kinds of capacities, from apartments to multi-dwelling buildings. There are basically four types of boilers available. These are electric boilers, gas boilers, commercial boilers and instantaneous water heaters. Electric and gas type boilers are also divided into central heating domestic hot water, only central heating, and central heating with boiler using.
