Plumber says the flow and return are connected in reverse for UFH manifold

[BennyHatson]

Hi everyone, the new place we're moving to has UFH. The plumber came and indicated that the flow and return is reversed, as in the top row you see here is colder than the bottom row. He said that in all UFHs he's seen, top row needs to be the flow. Would this cause any problem if I went ahead and used it this way? I know that the valves should be color-coded and it's misleading if the red valves stay as the return, but would this be inefficient in any way?

 

[Madrab]

If that is all there is to the UFH then it looks to be just manual open/closed valves, if that's the case then it wouldn't matter.

UFH Flow direction is only important when it's using a a manifold with a pump, blending valve and flow meters, they all work in a specific direction so flow and return would be important.

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