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Steam boiler Sight Glass Gets full and will not empty when furnace drained

Kev82
Kev82 Member Posts: 4
Have a problem with the sight glass that will not go down when furnace is drained. It is a 7 year old gas fired Steam Boiler. I believe the drain line from the glass is rusted shut. How can remove this blockage?

Comments

  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,406
    Its clogged Buddy.  The best thing yiu can do is 
    1) Shut switch off & Drain boiler.
    2) Gently loosen nuts &  take out glass.
    3) Screw out the Guage Glass Cocks.
    4) Tap them on the concrete floor to loosen the splooge and mud.
    5) Try to blow through them.
    6) Run hot water through them till clear
    7) Ball up a piece of paper towel and plunge the glass vial  like cleaning a shotgun a few times using the rod that protects the glass.
    8) If all is clear, Teflon tape the GG Cocks 
         Clockwise,  pipe dope over that. Tighten
          And sqaure them up & put glass back 
           Et cetera.
    ***If its REALLY CLOGGED AND OLD GET A WHOLE NEW KIT

    MAD Dog 🐕 

    PC7060
  • Jamie Hall
    Jamie Hall Member Posts: 24,183
    and don't forget to make sure the openings into the boiler are clear...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • 109A_5
    109A_5 Member Posts: 1,388
    Hello @Kev82,

    Often you can remove the valve and use the protection rod to clear the horizontal blockage.
    And / or remove the sight glass drain and use the protection rod to clear the vertical blockage.

    Go to 5:40 if you don't want to watch the whole video.
    https://youtu.be/t5E209rjLMk

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    Gordo