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Radiator vent type?

VickiS Member Posts: 51
I'm sorry for the angle of these pictures but all my radiators have covers on them which makes it near impossible for me to get good pictures.  Are either of these radiator vents adjustable?  Can you tell what type they are?  I have others that are clearly adjustable...either are marker with a slow/fast dial or I can a indention where I would put a screwdrive to turn...but these two I have no idea.  Thanks so much for the help.

Rod - if you happen to read this, did you get the email I sent you the other day?  It was not related to this current question.


Guess it would help if I attached the pictures...


  • crash2009
    crash2009 Member Posts: 1,484
    The first one

     looks like a Gorton or Maid O Mist.  The second I can't even guess.  You could maybe put a mirror down there and take a picture of the reflection.  That might help us identify it. 
  • Steamhead
    Steamhead Member Posts: 16,728
    Second one

    is an older Hoffman 1A or 2A. 
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849

    If it were a Maid-o-Mist there would be a hole on the top with the number or letter stamped next to it.

    I'm not sure about that other one either. If I had to guess I'd say it was a Hoffman 1A that's had something done to it.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Why adjust ?

    Are you having balancing problems. See if you can locate the main vents, and post their pictures, as well as pictures of the boiler piping.--NBC
  • VickiS
    VickiS Member Posts: 51
    edited November 2012
    Re: Vents

    Thanks for the information!  It is always appreciated.

    Yes, problems with the radiators although I'm sure the main problem is with the main vents.  I've attached pictures.  The first two are the mains vents.  The third is kind of a longer offshoot line and the last is on the dry return.  Steamhead identifed the type in another post as a Hoffman #76 & #6 which I know are not right for our system so I know they need to be replaced.  Would a Gorton 2 be the correct type to replace with for the main line?  They are 66' and 44'.  I'm not sure about the two lines...they are 22' and 25'. 

    I have some radiators the get really hot while other barely so, some hiss loudly and others don't mak a peep, so I've been trying to figure out what types of vents are on them so I can plan a strategy of what to do with them.  I'm hampered with identifying them since I can't really see them.  I'll give Hap's mirror suggestion a try although some of these spaces are so tight or the vent is so far down that I'm not sure that will work.

    After reading another post, I have an additional question unrelated to vents...what does it mean when the site glass is at the correct level but after one cycle of heat the water drops about 1 1/4"? Every cycle after that seems to remain at that same reduced level..it just seems to be that very first cycle where I've reset the water level that it drops.

  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    edited November 2012
    Main vent selection

    If there is enough headroom, I would put a gorton #2 on each.

    Did you tell us what your pressure was?

    Hissing radiator vents would indicate the inadequacy of the main vents, which do all the work of letting the air out of the pipes and steam chest, as well as possibly too much steam pressure.--NBC
  • VickiS
    VickiS Member Posts: 51
    Re: Pressure


    Unfortunately I don't have an accurate pressure gauge on my system yet.  It's one of the first things you guys recommended when I was having problems a few weeks ago.  It's on my to do list...just a matter of finding the time...my list is quite long at the moment.  I can say the pressure from the boiler gauge, even though I know it's not accurate, is usually right around 2 when the system is running which is a far cry from the 5 which is where it was when I first posted here a few weeks ago.

    Two of the 4 have the head room to accommodate a #2 but others are too close to the ceiling.  One I could probably put smaller ones on an antler to build up to the venting the capacity of a #2 but I don't think I can even do that for the last one...it's kind of wedged in a box between floor joists.

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