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Boil the water for radiant ?

nibs Member Posts: 516
Our small city does not chlorinate the water, and the bio film will grow quite nicely in warm pipes creating a lovely green slime. Our system uses 20 gallons +/- of water, so boiling would not be too onerous a task.
What is the general opinion?
We could chlorinate but it seems to me that sterile water would be best.
Wondering what effect would boiling have on the entrained air/ O2 levels?
PS the city wins international water taste contests so they are not about to add chlorine.


  • Jamie Hall
    Jamie Hall Member Posts: 23,455
    The biofilm will only continue to grow until it uses up the nutrients and oxygen in the water. Then it will stop. Provided you are not adding water to your system regularly -- and you shouldn't be -- it shouldn't be a problem. You can always add a corrosion inhibitor or oxygen scavenger -- in small quantities -- if you like.

    Or boil the water.

    Or use DI plus the inhibitors...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • mikeg2015
    mikeg2015 Member Posts: 1,194
    Boiling reduces the air. On steam boilers you usually “boil it out” after filling or adding a lot of water. Probably want to chlorinate and boil. Boiling the water doesnt’ sterilize the pipes themselves.
  • hot_rod
    hot_rod Member Posts: 22,271
    I think you would need to first run a cleaner in the system to remove any biofilm. Elevating above 160F would kill anything living in that film.

    Then add good fill water DI or DM with a hydronic conditioner to control ph, scavenge O2, add a film provider to prevent corrosion.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • nibs
    nibs Member Posts: 516
    Thanks all for the responses.
    At this time the system is dry, we filled it and ran it for about three weeks, then drained and blew out the boiler and loops, am concerned about our return in the spring when we re fill it.