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PSI at 7. Trying to find main vents.

After reading 2 Holohan books, became brave and went down to check out the set up in our new old house. Our PSI is at 7, despite the cut in at .5 and the Diff at 1. Trying to figure out if we have main vents or not ( we have 2 supply mains). I've located what look like vents to me, but they are at the end of the returns, right next to the boiler. I thought main vents are supposed to be at the end of the supply main. I came across what looks like a potentially capped main vent - but of course I'm confused by these other vents.

Any thoughts are appreciated.


  • BobC
    BobC Member Posts: 5,473
    edited February 2013
    How long and what size

    Those look like gorton #1's, how long is the main and what size pipe, what size is the return and how long is it? That picture looks like it might be a good place for a main vent but it all depends on how long and what size your piping is.

    What issues are you having with the system? For a start TURN THE PRESSURE DOWN! Steam systems work best at low pressure (1.5 or less).

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • JeffM
    JeffM Member Posts: 182
    vents may be ok, look first at pressure

    I wouldn't worry about the venting right now. It may not be perfect, but your high pressure would concern me more. In spite of your appropriately low cut-in and diff, the control only maintains those pressures with a clean pigtail connection to the boiler. I'd start by having someone check the pigtail, as that being plugged would lead to high pressures.
  • Cuffaro
    Cuffaro Member Posts: 6
    length and size

    I just measured Main 1 and Return 1. Main 1 is an 8" circumference (so, 2" pipe?) and it runs 28 feet. Return 1 is 5.5 circumference (1.75" pipe?) and runs 27.5 feet. Main and Return 2 are same sized pipes, but run much shorter (under 12 feet). Didn't see any potential pipes at end of Main2 that could be possible capped vents.

    The issues:

    1. Pressure at 7 PSI despite proper pressertrol settings.

    2. Gas bills astronomical.

    3. Water in gauge so dirty can barely see level.

    4. Certain radiators aren't heating unless thermometer is set 72+.

    Definitely trying to get the pressure down and thought changing pressertrol settings would help until I saw they were already set correctly. Trying to figure out what else to do on my own and what I can call in a professional to do. Just had system serviced 2 months ago (before reading books) and he didn't mention anything about the 7 PSI. Potential knucklehead.
  • Cuffaro
    Cuffaro Member Posts: 6
    will check pigtail

    Thank you for the advice. Had the system serviced 2 months ago. Would checking the pigtail be a routine item for a service call? I'm worried the guy is a potential "knuckledhead" - since he didn't seem concerned at the 7 PSI.

    If I called and asked them if they cleaned out the pigtail, is that something they would have recorded in their notes? Or would I just be wasting my time?

    Recommend anyone in NJ (central-ish)?
  • MTC
    MTC Member Posts: 217
    post a pic of your controls

    so we can see how they're set up, etc.

    you said there's water in the gauge? are there pigtails on your controls at all? there really shouldn't be any significant water in the gauge, it may or may not be working properly. your pressuretrol may have similar problems, or as has been mentioned, if they have pigtails, could be clogged.
  • Cuffaro
    Cuffaro Member Posts: 6
    pics of controls and dirty sight glass

    Thank you for posting - here are the pics. I misspoke - should have said dirty sight glass, rather than gauge. Sight glass was cleaned at the servicing 2 months ago and was crystal clear when he left. Now I can't see a darn thing.
  • MTC
    MTC Member Posts: 217
    Good old systems, lots of rust to screw up the sight glass...

    but it doesn't seem like it should be dirty all the way to the top like that, at least not this fast. I'll defer to the more experienced guys here, but that seems like it might not be such a good thing.

    The sight glasses do get dirty like that on these old systems though, and fairly quickly. If you have trouble reading it, what I usually do is put a small flashlight behind it shining towards you, and move it up and down the glass. This will usually let you see the water level through the dirt.

    I'm not familiar with that sort of sideways pigtail setup either. Might be normal, but I always see them coming out the top of tees... I assume that its not a problem to have them this way?

    Also, when you say your PSI is "at 7," do you mean that it cuts out at 7? Does it cut out at all, or just keep running at 7 until thermostat is satisfied? That could be the pressure that your system can continuously run and keep condensing, which would indicate a problem with the control. A plugged pigtail, since your controls are on one shared one, would effect both the gauge and the pressuretrol. I'd rather see those on 2 separate pigtails, so if one tail clogs, it doesn't effect both.
  • Cuffaro
    Cuffaro Member Posts: 6
    Always at 7...

    the gauge never moves from that position. What should be happening? Should it go down to 0 at any point and then back up when it turns on?
  • Mark N
    Mark N Member Posts: 1,115
    edited February 2013
    Broken Gauge

    If the pressure gauge is always reading 7PSI it is broken. The pressure should drop to 0 psi when the boiler is off. JStar is a steam pro in the central NJ area, his company is Ecuacool. Try "Find a Contractor". Your near boiler piping is not optimal. First it is done in copper and it looks that the take off for the mains is in between the risers from the boiler.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849
    Second picture

    Your second picture shows a Dole #4 vent on top of a vertical extension, as it should be. This vent has no float, so it has to be mounted high enough to prevent water from spitting out of it. It should have the same venting capacity as a Gorton #1, but they are prone to fouling. You can check it as you would any main vent, by holding a lit match, lighter or candle in front of the orifice while the mains are filling and seeing if it blows out the flame.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849
    This could be a dangerous situation.

    Your gauge is probably not working because the pigtail is plugged, so your pressuretrol won't work either, and there's no way of telling what the pressure really is, but the colder it is outside, the higher it's going to get, and this can be dangerous. If it gets too high, your safety valve could blow, and you don't want this to happen.

    Needless to say, the guy who came out two months ago should have caught this. Give Joe Starosielec a call. JStar is a top steam pro and a regular in this forum. He can make sure your system is working safely and give you an estimate on correcting that piping. He works really fast, but he's really good!
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Cuffaro
    Cuffaro Member Posts: 6
    Many thanks for all the advice...

    I have JStar lined up to come out on Tuesday. Now I'll know some of what he's talking about when I see him. This forum and website are the most helpful resources I've come across. Relieved to have found them. Thanks again
  • JStar
    JStar Member Posts: 2,752
    edited February 2013


    At the end of the day, testing all of the radiators, we found a section of main that was sagging near a few takeoffs. Looks like work had been done in that area, and the piping was a little mangled beyond a quick repair. The sag in the main was collecting condensate and causing a few radiators to breathe in and out before getting steam. This project will be scheduled for a later time.
  • Jamie Hall
    Jamie Hall Member Posts: 22,934
    Joe -- I'm sure you're on top of this

    but could this be the remains of a badly knuckleheaded vapour system?  In which case, the vents at the ends of the dry returns at the boiler would be quite normal.

    But it looks as though you do have some work to do here!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • JStar
    JStar Member Posts: 2,752

    This is pure one pipe steam. No vapour, unfortunately. Though, we will have a Richardson job to post about tomorrow!!

    We redid all of the supply piping and upgraded the vents. There is a potential plan to change the boiler in the near future. This was a short term repair to keep the fuel bills down, and make the system a little more efficient in the meantime.
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