What is the function of zone valves in terms of hydronic systems?

The function of zone valves in hydronic systems is to control water flow in specific zones. These valves play a crucial role in the distribution of heated water throughout a building's heating system. By opening or closing based on the temperature requirements of a particular zone, zone valves ensure that each area receives the appropriate amount of hot water for effective heating.

This specific control helps maintain comfort levels in various parts of a building and enhances energy efficiency, as only the zones that require heat are served. In essence, zone valves act as on/off switches that regulate the flow of hot water to different sections of the hydronic system, allowing for customized heating solutions in multi-zone applications.

Other options, while related to hydronic systems, do not directly depict the primary function of zone valves. Enhancing pump efficiency involves optimizing the overall circulation of water but does not pertain to the specific role of zone control. Increasing boiler pressure is not within the scope of zone valves; this is typically managed by the boiler's own pressure controls. Preventing backflow is a function served by different components such as check valves, which are designed specifically to stop reverse flow and protect system integrity, rather than controlling flow to specific zones.