What is the primary function of a zone valve in plumbing?

The primary function of a zone valve in plumbing is to control the flow of hot water to specific areas. Zone valves are used in hydronic heating systems to regulate the temperature in different zones or areas of a building. By opening or closing based on the heating demands of each zone, they allow for efficient use of hot water and optimal comfort levels within a structure. This functionality ensures that only the necessary areas receive hot water, allowing for more energy-efficient heating, reduced utility costs, and an overall improved heating performance. The correct operation of zone valves is integral to managing the flow of hot water in multi-zone heating setups.