Non oxygen barrier pex used by contractor

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genki
genki Posts: 8
in Strictly Steam

So I just discovered that the contractor has been using regular pex-b on the manifold to panel radiator runs in a closed loop conventional boiler setup. Am I wrong by thinking that the options are replacement, perpetual water treatment or heat exchangers/eliminating all ferrous components ? I knew that this setup needed work but it previously seemed manageable. I wasn’t planning on having to re pipe all of this too. Absolutely devastated and angry.

Comments

  • mattmia2
    mattmia2 Posts: 18,337

    pretty much. it should be oxygen barrier. treatment isn't a bad idea even with oxygen barrier because it isn't perfect but the oxygen scavenger will be consumed very slowly with oxygen barrier tubing.

  • genki
    genki Posts: 8
    https://forum.heatinghelp.com/discussion/comment/1908431#Comment_1908431

    This is good to know. I have looked at one product so far. But I would prefer to use it, or similar, as a “backup” so to speak and take care of the issue now.

  • hot_rod
    hot_rod Posts: 28,644

    what type of boiler. What temperature is it running?

    If it is a mod con it is a non ferrous boiler. So a stainless pump and Amtrol Radiant Pro expansion tank may be all you need to be non ferrous?

    If it is cast iron, steel piping, then a HX or ongoing Fernox treatment

    How often you boost the treatment depends a bit on the operating temperature. The higher the temperature, the higher the O2 ingress.

    A HX involves another pump, air purger, expansion tank and fill system.

    Even barrier Pex allows small amounts of O2 into systems.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Posts: 4,881

    "If it is cast iron, steel piping, then a HX or ongoing Fernox treatment"

    @hot_rod I used to use Fernox F1 and F3 on non-barrier systems, but now use Rhomar 922 for oxygen scavenging. Does Fernox make something equal?

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Peter49
    Peter49 Posts: 3

    Before deciding to replace all the pipework I'd confirm exactly which components contain ferrous metals including the boiler heat exchanger, circulator and radiators. A plate heat exchanger could isolate the non barrier PEX circuit from the boiler but it wont protect any steel components remaining on the radiator side. I'd also ask the contractor for the exact PEX manufacturer and part number to confirm whether the tubing genuinely lacks an oxygen barrier.

  • mattmia2
    mattmia2 Posts: 18,337

    Is this a new installation or is this existing? Is all the tubing non O2 barrier or just some pieces used to do some rework?

    And the most important question, what does the boiler manual say? If it says don't do it or you have a contract calling out O2 barrier then you have a lot more leverage to make them change it.

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