Water Heaters are systems that are intended to heat water to regulated temperatures for a variety of purposes. Familiar domestic uses of these systems include the heating of water to assist in washing clothes or dishes and taking showers or baths. Additional domestic uses of water heaters can be to heat the water in swimming pools and spas. In the typical water heater, the water is heated within the unit and is then circulated to the desired point of use or application by way of a series of pipes, pumps, and valves.
Three ways of characterizing water heaters are by their design, their fuel source, and by their intended application. Collectively, these methods lead to the following list of types of water heaters:
Types by design