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Is pex safe

leaking Member Posts: 35
Is pex safe to use for piping to radiators on boilers that can reach 200f. What if the aquastat fails and temps go higher. Is it even logical to consider Pex for high temp boilers where pressure may be 20 to near 25lb. It sounds risky and unsafe.


  • kevin_58
    kevin_58 Member Posts: 61

    Pex is rated 100 lbs at 180 degrees for domestic hot water
  • PEX Safety

    To answer your question, no, PEX is not safe to use in any kind of heating system unless you install your own safety high limit.  Ever since I had a runaway boiler that melted the PEX tubing supplying radiators, I've installed a high-limit aquastat on the supply piping.

    If you are uncomfortable even with the use of your own high limit, use copper.
    Often wrong, never in doubt.
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083

    it is safe.

    Is there something more behind this question?
  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    why the heck

    would you allow your boiler to run to 200 deg F in this day and age???
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
  • Robert_25
    Robert_25 Member Posts: 406
    Solid fuel boiler

    Most of the barrier pex I have seen lists a rating of 80 psi at 200 degrees F.  Look up the specs on your tubing to be sure.

    NRT_Rob, 200F is not uncommon with wood or coal fired boilers in the spring and fall.   e.g.  I have a dump zone set at 200F on my coal boiler.

  • NRT_Rob
    NRT_Rob Member Posts: 1,013
    so add

    a tempering valve...
    Rob Brown
    Designer for Rockport Mechanical
    in beautiful Rockport Maine.
This discussion has been closed.