How do smart valves in a central heating system save energy and therefore money?

Question

If each radiator calls for hot water when it needs it, won’t this be often and at different times, and therefore be a roughly similar energy cost to doing it less frequently but all at once?

In: 1

Answer 1

My understanding, and I’m not an engineer, is that it’s not to save energy but rather to keep a consistent on-demand flow of hot water. It’s “smart” in a sense that you won’t run out of hot water halfway through your shower