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How do I know if garage sale radiators are good?

Hi, our home is heated with steam radiators. I bought some as "back ups" at a garage sale. How do I know if these radiators, that are now sitting in my garage, are in working order or not?

Thanks for your help!


  • Mark Hunt
    Mark Hunt Member Posts: 4,909

    If by "working order" you mean "not cracked" then you will need to pressure test them.

    This could be done with air or water. Any holes would have to be plugged and then you would pressurize the radiator through one of them.

    The method you choose for pressurizing will determine what type of adapter you will need.

    For a water test you would need a bushing with a hose bib to attach to a hose.

    For air you would need a bushing and a connector for a compressor.

    If you use an air compressor, DO NOT over pressurize the radiator!!!!!!!

    Hope this helps!!

    Mark H

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  • Terry
    Terry Member Posts: 186
    safety first

    Much safer to test with water ! (it doesn't compress like air does)
  • John@Reliable
    John@Reliable Member Posts: 379
    Yard sale

    Why would you need back-ups?,they must be sized to work right on your system.But then again I can't pass up a good yard sale bargain!Test with water and if you do ever need then make sure they are the right size for job.
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928

    If you didn't get the original valves and angle unions with the rads, you'll probably have to remove the bushings and other half of the union connections. Unless you find the valves/angles by the same mfgr. you're unlikely to get a tight connection. They can be REALLY tight. Use a big wrench and a breaking bar.

    Typical household water pressure can sometimes cause very slow, weeping leaks BETWEEN sections on rads assembled with push nipples. You can easily tell if they use push nipples as there will be threaded rods running horizontally through the rad. Hot water systems operate under much lower pressure and this type of leak is unlikely to recur.
  • Earthfire
    Earthfire Member Posts: 543
    air test

    to test the radiator for leaks fill with water and pressurise to about 30 to 40 psi with WATER, no more . Your heating system should never see pressures that high. If you use air to pressure test if a crack lets go the resulting schrapnel flying thru the air could very easily be a fatal missle, not to mention a hole in the wall. With water behind that piece of metal it won't fly. For safety sake DO NOT USE AIR use water.
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