The diagram illustrates a typical system configuration of medium or large homes distributed over several levels. In these cases, the domestic hot water (DHW) requirement is met through a centralized production system with storage, which guarantees higher performance than instant production systems.

The production of DHW is entrusted to a sanitary kettle, powered by a boiler, capable of raising the water temperature above 65°C. The distribution temperature is regulated by means of a thermostatic mixing valve (TMV), which ensures delivery at a constant temperature and protects against burns.

The distribution of domestic hot and cold water (DHW and AFS) is of a manifold type, with the presence of main manifolds equipped with general and single interceptions, which supply the terminals of the various rooms (bathrooms, kitchen, laundry).
 This type of scheme allows a modular management and facilitated maintenance for each group of users and an optimization of the routes and balanced pressure on several levels.

Since the distances between the kettle and the points of use can be significant, an DHW recirculation circuit is implemented that guarantees rapid hot water delivery times and maintains a stable temperature near the points of use.

The combined presence of a kettle (>65°C), thermostatic mixer and continuous recirculation makes it possible to implement thermal disinfection of the sanitary network, useful to combat the proliferation of legionella. This operation must be carried out manually, during periods of non-use (e.g. night or absence), to avoid the risk of burns to the user.