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backflow preventer leaks when filling radiators


I drained my hot water system and had my radiators sandblasted and painted. I replaced them and tried refilling the system, but the backflow preventer leaks like crazy. Any ideas?

Thanks for your help!



  • Jamie Hall
    Jamie Hall Member Posts: 22,914
    You mean ideas

    beside replacing it?  If a backflow preventer is leaking -- usually through the atmospheric vent -- it isn't likely to be worth taking apart and fixing, unless it is a very big one (say 3 inch and up).

    I'd just replace it...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    Leaking back flow

    What make is it? Our Watts back flows can apparently be repaired if needed, but when checked every year, they have no problem. --NBC
  • travlintom
    travlintom Member Posts: 2

    Thanks for the replies. It's a Hersey and it'Is not big, but is on a 1/2" pipe.

    And is it necessary, because I've noticed that there is a shutoff valve between it and the boiler, and if I close the valve the backflow stops leaking.


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