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Leaking radiator air vents?

Hello everybody
I have a one pipe steam system hooked up to Weil Mclain EG 40 gas fired boiler. Thanks to you guys, I have been paying more attention to my steam system since I moved into my house last winter. After I changed some of the vents, all the rads heat up quietly and about at the same time. I can occasionally hear pipes contracting when the steam heats them.
However, one thing puzzles me. Recently I replaced some of the hissing vents with cheap Maid o Mists from Home Despot. They worked quietly with no signs of leaking steam. But at this point I was already obsessed with steam efficiency and decided to check all of my vents with the mirror to see if it fogs up.
Since my rads do not heat up all the way during the day I checked the vents in the morning when the system is coming from a 3 degree nightly setback. The result was that almost all of the vents were leaking a little bit of steam. The mirror would fog up at the spot where the went hole is, and a little bit of condensate would form on the mirror glass.
Thinking that Maid O Mists failed, I replaced them with more expensive Gortons. But Gortons did exact same thing where a glass would fog up and a little condensate forms at the spot where the went hole is. I have also checked the older vents, which I still didn’t replace, and they were doing exact same thing! Only one of the rads vent closest to the boiler was bone dry. Gorton #1 main vent does the same thing too. Again, this is only noticeable when using a mirror or a small piece of glass.
I know that whoever piped that boiler did a horrible job. My header is not even close to the minimum specs stated in weil mclain manual. My riser is undersized and certainly is much shorter that the 24 required inches. I had a pro come out and repipe the return lines, since they were also piped wrong. I did not touch the header due to budget constraints and the fact that all the rads were heating up at about the same time and kept the house nice and cozy. Also, the boiler is 8 years old and I think it would be rather difficult to repipe it at this point. I do not have any water hammer in the system.
So are the vents suppose to work like that where they release a little bit of steam only noticeable if you hold a piece of glass close to the vent hole? Or all of my vents have magically failed again? Can the bad piping contribute to that (wet steam)?
The system pressure is set to 1 cut in and 1 differential inside the grey pressuretroll box. The system cuts out at 2 PSI only at the very end of a set back cycle.

I know the piping is an abomination but I will post the near boiler piping pictures anyway.

I apologize for a lengthy post but I needed to vent somewhere (no pun intended) since my research on the internet regarding this predicament did not return any meaningful results.
P.S. I need to add water to a boiler about once a month during the dead of the winter. Is it excessive?
Also I recently replaced Gorton #1 main vent on the picture. I wanted to put #2 there but couldn't fit it and I am not comfortable enough building an antler. The main is about 65 foot long. I know I am undervented.

Thank You!


  • Abracadabra
    Abracadabra Member Posts: 1,948
    edited November 2015
    1 - Home Depot doesn't carry MOM vents. They carry Watts SV vents. They are one of the cheapest vents around. I wouldn't use them. Sorry... I take that back... I just checked their site and it appears that certain stores carry the MOMs and others carry the Watts. I guess it's a regional thing.

    2 - You should be able to fit at least one Gorton #2 main vent there easily.

    3 - Steam vents will normally open and close and you'll get a bit of steam leakage every now and then.

    4 - The current gauge you have is not a good indicator of pressure, especially in the 2 PSI range you say you are hitting. Get a 0-3 PSI gauge installed. 2PSI on that gauge might actually be 3ish on a more accurate low pressure gauge.
  • The height allows to fit Gorton #2 but I can’t screw it in because the nearest pipe on the side prevents it from screwing it properly.
  • Fred
    Fred Member Posts: 8,540
    It looks like you have plenty room next to that pipe, especially if you take the insulation off until you mount the Gorton #2. If not, put an elbow, a short nipple and another elbow on to move it away from that pipe.
  • vaporvac
    vaporvac Member Posts: 1,520
    Do you have enough height for a union?
    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
  • BobC
    BobC Member Posts: 5,380
    If you have room to thread in a close nipple with a elbow on it you can make more room.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Abracadabra
    Abracadabra Member Posts: 1,948
    If the #1 will spin on there, a 90 should. And if you happen to not have enough space for a 90, a 45 will give you more clearance. add another 45 to get to horizontal+nipple+90+#2