UFH not working - suspect issues at manifold

[Mjward]

The manifold metal bar ie the part where the UFH pipes are connected, is getting hot on both top and bottom, almost identical on both around 40c. Plastic pipes themselves not warming at all

 

[ShaunCorbs]

Open one flow meter fully open

 

[Mjward]

Thats what I've done so far. Opened one fully, closed two fully, given it some time but nadda. Same for all three loops.

I'm confused how both top and bottom can be hot if loops themselves aren't flowing. I thought only flow side was fed the warm water from the flow mixer. From the piping on mine it looks like there is a connecting (vertical) pipe from the flow mixer that is perhaps simultaneously feeding both top and bottom bars

Open one flow meter fully open

 

[MOSSEP]

It could be that you have inadequate flow to your actual manifold, your main system pump could be the issue. Isolate the other manifold that is working and see if it gives an improvement.