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Air Eliminator Trap

I have an air eliminator trap that has an open air vent on the top (3/8").  The steam is literally "flying" out of the vent whenever the boiler is making steam.  Not being at all familiar with this device, I'm looking for advice as to how to deal with this.  The air trap has "Pattno E90" on the side.

Comments appreciated.

Picture enclosed.


Jerry A. Valentine


  • JStar
    JStar Member Posts: 2,752

    Do you have traps on the radiators? They are probably failing open. Steam should never make its way back to the Air Eliminator.
  • Jerry Valentine
    Jerry Valentine Member Posts: 15

    Yes, there are traps on the radiators.  I can't believe they are all failing.  If need be, I will need to check.


  • Jamie Hall
    Jamie Hall Member Posts: 21,113
    Probably not all failing...

    it only takes one to cause the problem your seeing.  Just one...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Jerry Valentine
    Jerry Valentine Member Posts: 15

    How would I find out which one is the problem?  Can I measure temperatures?

  • Ban
    Ban Member Posts: 79
    Cross over traps

    The cross over traps tend to be right near that air check. I would start there, they got over looked alot. The attached photo is my Dunham Air eliminator and you can see the cross-over trap coming from the main.
    Richard Ban
    Detroit, Michigan (Dunham 2-pipe vacuum)