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.

Best temporary venting solution

Hi all,
I'm back.

Thanks to the Wall, at my last house I completely repiped my dysfunctional one pipe steam system and got things working like an oiled top. Then I sold the house.

Recently moved into a place with what is currently (not sure how it started life) 2-pipe vented (rad vents) steam- with a few one-pipe rads thrown in. There are no main vents. I will likely repipe the mains and will definitely replace the wet returns next spring and can add main venting properly then, but in the meantime I'm looking for quick-and-dirty solutions.

I'm thinking about either tapping the mains (probably 3/8") at the end of the runs to add some venting in the basement, OR adding a T at the steam inlet side of the final rads on each main to add a vent there.

Now, I've read about people adding a main vent at the radiator in this way when it's difficult to add a vent in the basement for some reason, but I don't really have that limitation.

Any thoughts on the best (temporary) solution between these two approaches?



  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,564
    You could try putting Gorton D’s on the last couple of radiators on the mains, and see what difference that makes.
    If the main is a smaller diameter, then a series of smaller tappings would be more secure, with Gorton D’s once again.
    Keep the pressure very low to minimize the air removal problems people have had by over-venting individual radiators.
    Slower vents on the others should encourage the main to fill first, all the way to the end.—NBC
  • Steamhead
    Steamhead Member Posts: 15,331
    Hey Patrick- good to hear from you!

    I've been known to tap 1/2" pipe thread into a cast-iron fitting to add a Gorton #2 vent. Can't remember if we did it that way at your old house though.

    Still in the same area?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • PatrickNorth
    PatrickNorth Member Posts: 19
    Hi Steamhead-
    Yep, still in the same area. Actually just a few blocks down on the same street!
    Yes, now that I think of it, I think you tapped the main to add a Gorton D as a temporary fix until proper fittings could be cut in. That's all the endorsement I needed so I went ahead and tapped the mains to add a Gorton #2 to each of the two shorter branches and a Barnes & Jones "Big Mouth" to the long run.
    Hard to tell because things haven't gotten cold enough around here to really give the system a workout, but it's definitely heating up a lot faster and not cycling on pressure.

    This is probably all the time I'll be able to devote to the steam system for now, apart from swapping out some radiator vents when I get a better sense of how it's performing- just too many other projects going on here. But I'll for sure be replacing the decrepit wet returns ASAP, and I want to do some more investigating. Some of the crazy vestigal piping in the basement suggests it was originally some flavor of vapor system. Not sure that it ever will be again, but I'm curious, anyway.