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Pressure, main vent questions

Hi, I'm a newbie. I have a 2 story house in Brooklyn, NY and it has steam heat. We converted it from oil to gas a few years ago. The main vent in the basement has been leaking steam. It is hissing every time the heat is on and the walls and ceilings around it has water drops on it. So I began researching this problem. I have had the vent replaced. I had a plumber come in and he said it shouldn't happen. My questions are:

1. What could be causing this? I did finally realize it's using a Hoffman 45 air vent but this isn't a main vent but a convector vent. It was using it ever since I bought the house. Am I using the wrong vent?

2. In my research, I was reading about the pressure setting on a steam system.  Everyone is saying cut-in pressure should be .5psi. I saw that m cut-in was at 2 psi and the main pressure was at 10psi. Are these settings correct? Is the pressure causing the main vent problem?

3. The plumber who installed my boiler suggested that I use the Hoffman 41 vent for my radiators but it is a convector vent. Is there a difference. Oh, this plumber refuses to come in to take a look at my main vent problem. He always ends up ignoring my appointment.

4. Are there any specialized steam specialist in Brooklyn that I can hire to take a look at my boiler and main vent.

Thanks for any help.


  • jpf321
    jpf321 Member Posts: 1,567
    go onto brownstoner.com and look for posts by MasterPlvmber

    go onto brownstoner.com and look for posts by MasterPlvmber He owns/works for Gateway Plumbing & Heating .. a few good steam outfit in BK .. but they won't help me here in QN :-(

    Or get The Lost Art of Steam Heating (link in signature) and delve into the wonderful world of steam.

    You pressure is too high, maybe your gauge is wrong, or you are looking at the wrong pressuretrol.

    Get proper main vents, although right now the jury is out on what those are.

    High pressure could certainly be killing your main vent .. and certainly wasting your money.

    I'm always interested in seeing another system simply as a curious homeowner myself, and b/c I've been told to get out in the field more. So if you like, I'm happy to stop over and have a look and give you my thoughts first hand. "Contact me directly" if you like.
    1-pipe Homeowner - Queens, NYC

    NEW: SlantFin Intrepid TR-30 + Tankless + Riello 40-F5 @ 0.85gph | OLD: Fitzgibbons 402 boiler + Beckett "SR" Oil Gun @ 1.75gph

    installed: 0-20oz/si gauge | vaporstat | hour-meter | gortons on all rads | 1pc G#2 + 1pc G#1 on each of 2 mains

    Connected EDR load: 371 sf venting load: 2.95cfm vent capacity: 4.62cfm
    my NEW system pics | my OLD system pics
  • Answers?

    Hi - Your basic problem is your steam pressure is way too high!! A residential steam system is designed to run at under 2 PSI. The lower - the better! It needs to be adjusted way down.

    For a steam professional- Look in "Find a Professional" at the top of this page. Skip the Zip Code find section and scroll down to the States and look under your state. (The zip code software is new and still has some bugs)

    Answers to Questions:

    Question 1 : Hi pressure will destroy vents. Both the Hoffman 45 & 41 are the wrong vents for you applications.  As you mentioned the Hoffman 45 & 41 are convector vents. For your main vents I would either use a Hoffman # 75 or a Gorton #1 or a Gorton #2  The venting capacity of the Gorton #2 is 3 times more than a Gorton #1 and the Hoffman #75 is about between the two Gortons. 

    Question #2 - A cut in of 0.5 PSI and a cut out of 2 PSI is a good place to start. Try that and see how that works. If you can go lower that is even better. But in any case no more that 2 PSI MAX!   Pressure over 3 PSI destroys vents!

    Question # 3 - Vents for  residential steam radiators.

    I've just listed adjustable vents. There are fixed orifice vents available also.

    Hoffman 1A  (Adjustable) Hoffman Part # 401422

    Ventrite #1 (adjustable)

    Dole 1A (Adjustable)

    Heat Timer Vari Vent (Adjustable)

    A lot of the people on the Wall are using Pex Supply as a source for vents. You can look them up on the internet.

    I would highly suggest you get a couple of books that are available on this site. The first is "We Got Steam Heat" http://www.heatinghelp.com/products/Books/5/61/We-Got-Steam-Heat-A-Homeowners-Guide-to-Peaceful-Coexistence

    and the second is "The Lost Art of Steam Heating"


    Both books are written so the homeowner can understand them. Both are easy humorous reading, packed full of info and diagrams on steam heating and in a few evenings reading you'll know a whole lot more about steam heating. My copies have paid for themselves a hundred times over.

    I hope this has answered your questions. You might want to take a look at what is called "Off the Wall" in the Resource section at the top of this page. Look in the Library as it is a source of a lot great articles on steam heating.

    - Rod
  • pressure too high!

    i would concentrate on getting the pressure down as low as possible. a good low-pressure gauge [gaugestore.com 0-2 psi]  will show you what the pressure is. 

    at the same time, get a good vent, such as a gorton#2 [or several] on the main lines. after the system has settled down, you can then check your radiator vents for function. if they are old hoffmans, they may have survived the over-pressure.

    since good steam men are apparently so busy in your neck of the woods, i would have JP over to look at your system; while you are waiting for the steam pros to arrive. he may be able to show you will  some things you can do yourself, as far as maintenance and adjustments go. at the very least, you will learn how to observe and diagnose steam problems. when this is all done, and the system is working as it did when new, you will be amazed how you tolerated it before.--nbc
  • xomaru15
    xomaru15 Member Posts: 2
    edited February 2010
    Thank you and 1 more question

    I want to thank everyone for their help. I am going to order some new vents from PexSupply and lower the pressure. But before I lower my pressure, I have one last question. I see a cut-in and main pressuretols but I can't find the cut-out or differential. I looked at another post on heatinghelp and his pressuretols look exactly like mine: http://www.heatinghelp.com/forum-thread/128980/Boiler-Cutting-out-on-Pressure#p1183759

    I am attaching my pictures. Is my pressuretols the same as DanS's? The gray one is the active one and the red one is the backup? Is the differential is actually inside the gray box? They both pigtail back to the same box as seen in the last picture.

    I am not handy myself and heard about the dangers of changing pressure (as least raising the pressure) in a steam system. To lower the pressure, is it simple enough for me to do?

    JP, I may take you up on your offer to come by.

    I'm going to try and follow everyone's advice of changing the vent and lowering the pressure. I'll update you guys in a few weeks.

    I want to thank everyone again for their help.
  • jpf321
    jpf321 Member Posts: 1,567
    edited February 2010
    p-trols ...

    firstly .. the pigtail is the curled piece of metal pipe which exits the BOTTOM of the devices .. not the electrical armored cable which exits the side.

    second .. yes turning down the pressure is easy .. it should only be done on the GREY one .. see screw on top .. turn to left(?) so that the little gauge guide by the numbers lowers to 0.5 ..

    lastly, .. yes, the differential on the GREY unit is on the inside .. it should be a white dial with numbers ... turn off your boiler safety switch while you have the GREY box open, should be a red electrical switch somewhere in your basement or on basement stairs.  when you open up the GREY box using single screw bottom front center .. look for white dial and turn until #1 is facing front. then turn your boiler safety switch back on.
    1-pipe Homeowner - Queens, NYC

    NEW: SlantFin Intrepid TR-30 + Tankless + Riello 40-F5 @ 0.85gph | OLD: Fitzgibbons 402 boiler + Beckett "SR" Oil Gun @ 1.75gph

    installed: 0-20oz/si gauge | vaporstat | hour-meter | gortons on all rads | 1pc G#2 + 1pc G#1 on each of 2 mains

    Connected EDR load: 371 sf venting load: 2.95cfm vent capacity: 4.62cfm
    my NEW system pics | my OLD system pics
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