Safe heating should not be taken for granted. For a long-lasting and efficient heating system, conditioned heating water is required. This is because its composition has a major influence on the trouble-free operation of a heating system. Perfectly treated heating water prevents scale formation, corrosion and silting. The requirements for heating water are described in detail in the guideline VDI 2035

In addition, drinking water must be protected against contamination from heating water in accordance with the valid standard DIN EN1717. When filling the heating system, this standard requires the use of a protective valve to ensure reliable separation of heating and drinking water. Because, especially when refilling via a temporary hose connection, there is a risk that heating water can get into the drinking water.