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SnowmeltSnowmelt Posts: 1,061Member
Does anyone use the onix tube from watts for radiant anymore?


  • hot_rodhot_rod Posts: 11,252Member
    What advantages do you see with it?
    Flexibility was one strong selling point. The original Entran was very soft and flexible. It was a nice tube for remodel and renovation work, no expansion issues, quiet, easily threaded in tight places.
    All the layers added over the years have made it not as supple, more $$ and less conductive to heat transfer, it seems.

    It is still haunted by sludge concerns?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • kcoppkcopp Posts: 3,324Member
    edited March 6
    I just worked again on a Staple up system w/ Onix yesterday.
    This is a system I have power flushed added a Caleffi air/dirt/ magnetic separator and added a Non ferrous extrol tank. Furthermore I cleaned the system w/ Fernox, flushed it out and added a good amount of inhibitor.... Still had a issue after just 3 months. I was surprised by the amount of crud in the water.
    I am at the crossroads of whether to rip it all out and either do baseboard or radiant staple up w/ barrier pex…. so no.... no thanks.
  • psb75psb75 Posts: 84Member
    One of my largest and elaborate residential systems that I tend to has a whole lot of Onix in-floor radiation. Have already had to abandon a couple of loops on the manifold (no flow) because...the system was looking a lot like the pictures hot_rod submitted. Onix...just...NO. Its "haunted."
  • SnowmeltSnowmelt Posts: 1,061Member
    I was just curious because my wife wants to add radiant to rest of house. ( one section at a time. I did a job with onix with no complaints.
  • Tom_133Tom_133 Posts: 613Member
    No complaints as of yet. It typically takes 5-10 years depending on the job. I feel bad for the jobs I used onix, hopefully they call me to fix it, I will give them the best deal out of shame.
    Montpelier Vt
  • Solid_Fuel_ManSolid_Fuel_Man Posts: 1,454Member
    Use PAP or PEX with an O2 barrier. That is the problem with EPDM rubber oxygen barrier and lots of problems with rust/sludge.
    Master electrician specialising in boiler and burner controls, multiple fuel systems, radiant system controls, building controls, and universal refrigeration tech.
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