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Heatway/Watts Onyx Tubing

markotah Member Posts: 36
I have a system installed for about 6 years now for floor warming. Last year we had an issue with flow and black slime that plugged the mixing valve and flow check. This year the problem is much worse and the heat output was never 100% and is dropping off. The tubes seem like they are now plugging. Has anyone elso seen this problem? Any possible solutions?



  • TheDevilHimself
    TheDevilHimself Member Posts: 1
    Onyx goo

    I am not aware of any issue like that from Onyx piping sold by WattsRadaint.

    Heatway (now out of business) sold a rubber tubing called Entran. It was made by Goodyear and had many reports of  the issue you're describing. The lawsuit between Heatway and Goodyear is what eventually lead to the fall of Heatway.

    Anything other than water in your system?

  • NoRegrets
    NoRegrets Member Posts: 1
    Onyx Tubing

    I am having the same problem. Black slime clogging my radiant system. I've flushed it out with water but it seems to come back and degrade the temp on the return line, seemingly due to restricted flow. Onyx told me to use Sentinel biocide. I have no specific protocol, and I can't find Sentinel or any other suitable biocide in the states. Seems like this is a problem that should be addressed by the manufacturer...
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Not personally, but...

    I have a very good friend in Summit County who refuses to work on Onyx systems any more. Can't run enough chemicals through to clean it up, and the gunk just keeps on a comin' back.

    Where accessible, he rips it out and replaces it with PEX.

    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
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