A hot water vessel is used in production of domestic hot water. The hot water storage tank, or hot water cylinder, can be connected to the heating system through district or central heating, or it can contain its own heat source.
One or more heating spirals connected to the heating system are mounted in the vessel. Domestic cold water is added to the tank in the bottom, with the domestic hot water being removed from the top. If the domestic hot water system contains a circulation loop, then the circulation pipe will be connected to the middle section of the tank. The circulation pipe is connected to the cold-water pipe just before the tank for tanks without a circulation tap.
The vessel can also be outfitted with an electrical heating element, either in combination with heating spirals or as the only heat source. The heating element is placed at the top of the vessel. Hot water vessels at risk of corrosion should be protected with either magnesium anode or an electrolysis/catalytic system.
Grundfos circulator and water transfer pumps feed the hot water storage tank to ensure optimal domestic hot water production and recirculation.