Looking to identify black pex type piping material

older_installer

Just when you think you have seen everything! I get a call today from a homeowner who said they were not getting much heat in their 2nd floor baseboard radiation loop..It;s been like this since they purchased the home 5 years ago...So I go over, thinking it might be one of the obvious ( air bound, bad thermostat, bad circ pump)..

I try and purge that zone, and get very little water, and what water I get was a very rd rust color...Try some more and still very little water at the purge valve...Then I go exploring....saw the feed and return piping at the ceiling was a black pex or rubber material, no name anywhere on it, just the date 2002, and a reference to a boca report #....Then went up and checked the baseboard radiation itself...and this is what I found!

That same black tubing was used to connect each rooms sections of baseboard, returning inside the enclosure as well. The tubing was kinked where it made the 180 bend from the end of the copper baseboard to turn back with the return...But that's not the best!  I couldn't see where the joint was between the copper fin tube and the black tubing, so I yanked on the black tube and found it was run inside the entire length of the fin tube and continued on to the next room...and so on.. Yes the black plastic was run inside the fin tube, everywhere in that zone...the copper fin tube was a sleeve for the plastic...Would anyone have a clue as to what that material may have been? My gut feeling is that it is a non oxygen barrier product, and that is what is attributing to the red oxide color of the boiler water...

Should I plan on replacing all that piping back to the copper at the boiler, with a pex product connected to the fin tube, to alleviate future issues for the homeowner?

SWEI

could be Onix or HDPE

Can you upload a photo?

older_installer

identifying

Unfortunately, I had forgotten to take my camera with me..The tubing is black, and almost rubber like when I squeeze it...Don't think it's HDPE material..

As for diameter, it's slighly smaller than the id of 3/4" fin tube core

Nate87

Black pex

If it almost feels like rubber then it's probably onix. I worked on some radiant a couple months ago and it was black but it was more like pex.

older_installer

Yes, its onix

older_installer

Yes, its onix

removed the hose type type, and yes, it is marked watts onix...Could this be the reason the boiler water is bright red when I drain it...does onix have an oxygen barrier..Date code appears to be 02 on the onix....repiped with heatpex, and all is now fine....still dont believe that some clown ran the onix inside the 3/4"  fin tube instead of connecting to the ends..