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Non Oxygen Barrier Pex with Combi Boiler

I know non oxygen barrier pex is not advised for heating applications, but since it is already installed in my house it would be impractical to change it. All of my zones use turbonics toaster wall convectors which were originally piped with non oxygen barrier pex, there are no radiant zones. I want to switch it from an open loop system to a closed loop and install a combi boiler and small buffer tank since I have limited space. Will a combi boiler be ok with non-oxygen barrier pex or am I asking for trouble? Has anyone had success with a Combi in a closed look without oxygen barrier pex?

Are there any particular models that more appropriate for non oxygen barrier pex then others? A lot of the manuals seem to suggest that it may not be ok, but most are kind of vague about it.


  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    As long as EVERY component in the water stream is non ferrous, you should be OK.

    To be certain, check with the manufacturers to be sure.

    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.