What does a manifold do in an underfloor heating (UFH) system and why do they cost do much?

Question

I am trying to understand what the manifold does in a UFH system. It seems to just be an overpriced collection of T joins connect in a row with a basic valve on each.

What am I missing?

Answer 1

The manifold is used to distribute fluid evenly throughout the system, as well as allowing you to turn on/off zones (for maintenance and whatnot). Without one you may find that some zones get more heat than others, since the flow could vary from zone to zone (depending on the plumbing).