Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Condensate line 2 pipe steam

When I remove cover on trap and remove insert, I see water and there are air bubbles blowing up to surface. Water drains, but why the air? Is this normal?


    EBEBRATT-Ed Member Posts: 15,512
    Downstream of the steam trap you need air vents to let the air out of the system. I suspect you do not have vents or they are not working. The only exception to this would be if the returns go back to a vented condensate pump.

    The return lines should be pitched down away from the trap so the water returns to the boiler.

    If you pour water into the trap with the cap removed the water should drain back to the boiler. The air bubbles you see is the water displacing the air in the return line. Since there are no vents the air bubbles back up into the trap
  • Pumpguy
    Pumpguy Member Posts: 654
    To elaborate on @EBEBRATT-Ed's post, I would look for a water seal in the return line(s).

    If the returns are not piped for full gravity drain as originally designed, you could end up with a water trap, which will need upstream air pressure do displace.

    A classic example would be uphill piping to the inlet of a condensate pump's receiving tank.
    Dennis Pataki. Former Service Manager and Heating Pump Product Manager for Nash Engineering Company. Phone: 1-888 853 9963
    Website: www.nashjenningspumps.com

    The first step in solving any problem is TO IDENTIFY THE PROBLEM.
  • richarddowling
    richarddowling Member Posts: 28
    I think I will replace the Gorton air vent on the main line. I'll have to check and see if it is working when boiler is running.
  • Are there crossover traps in this system, and have they failed shut?--NBC
  • richarddowling
    richarddowling Member Posts: 28
    Not sure. Where would they be located?
  • Jamie Hall
    Jamie Hall Member Posts: 23,272

    Not sure. Where would they be located?

    Crossover traps are at the ends of the steam mains, above the mains, and piped over to the adjacent dry returns. They usually look like -- and are -- the same as the radiator traps.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England