Cast your minds back to ebuild and June 2015. I had a 40sq m concrete slab poured and put in 3x 75m (approx.)  loops  16mm pert-al-pert ufh piping (via Wunda). Also got all the parts to go with it. I did my best to connect up the manifold to pressure test the piping after noticeably denting one pipe during the install. It didn’t keep a seal during the pressure test on any of the 3 loops, not just the suspect one.   At least they had water in them for the concrete pour. I later found ou