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Should I Replace All of My Vents

I recently converted my home steam system from Oil to Gas, and installed a new 300,000 BTU boiler.  Replacing the boiler seems to have created 2 issues:

1.  There is tremendous clanging at start up

2. Several of the radiators have started either spitting or leaking water from the shut-off valve (this also seems to also occur mainly at start-up)

I currently have a number of diffrent types of radiator vents installed, and was wondering if converting all of the vents to, for example, Hoffman 1As or 40s would perhaps solve the problem.  I would greatly appreciate any thoughts.


  • New Boiler

    Hi-  It may not have anything to do with the vents. With a new boiler the first thing to do is check the boiler manufacturer's I&O manual and see if the installation instructions were properly followed.  Perhaps if you post some pictures of your new boiler here we could spot something that needs adjustment.  Try to get  pictures of  the boiler and the piping connected to it.  Take pictures showing all  4 sides of the boiler. That way we can trace the piping out.   What is the make and model of your new boiler?

    - Rod
  • Jamie Hall
    Jamie Hall Member Posts: 19,968
    If it started with the new boiler

    it's more likely something about the boiler...

    As Rod says, near boiler piping: if you are getting wet steam from the boiler, it is a near boiler piping problem, and some pictures will help see that.  Makes a horrible racket.

    Second, pressure: what is the new boiler set to?  Make sure that the pressure is set correctly!  1.5 psi max for the cutout... just because it's new doesn't mean that the pressuretrol was set properly, unfortunately.

    Third, and I hope not, water line: if the new boiler's water line (in the gauge glass) is significantly different from the old one -- either way, either too high or too low -- that can create all kinds of problems.  Check that.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,238
    We need pics

    Near boiler piping pics help lots. also just how big is your home? 300KBTU is a fair size boiler. Call a pro, buy Dans primer books on steam, if you don't already have them, and what was changed to go to gas? Was it just the burner or the whole boiler?
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • kevinfaz
    kevinfaz Member Posts: 3
    Here are the Pics

    Thank you for the replies.  I have attached pictures of the boiler.

    The boiler was replaced about one month ago.  I did have 2 professionals tell me that I needed 300,000 KBTU (they measured the surface area of the radiators).  The house is nearly 100 years old, and I suspect that the radiators might be a bit oversized.

    I greatly appreciate the help.
  • Bill_110
    Bill_110 Member Posts: 52
    Boiler Riser

    It looks from the picture like you only have one boiler riser, with a 300,000 Btu boiler that probably gives you too much velocity and very wet steam. The lost art of steam heating has a simple calculation you can make where you plug in your pipe(s) sizes and pressure and generate a velocity, which you can compare to the ideal. 

    There is not too much you can do to compensate for this without correcting the near boiler piping. I think Dan's book mentions that sometimes steam pressure is actually raised in an attempt to compensate for this high velocity, but this will not really cure the problem. 

  • Boiler Info

    The pictures are a big help!   A few  of more questions.

    I'm wondering a bit about boiler sizing.

    1. How big is your house?

    2.How many floors?

    3. How many radiators do you have?

     I see your boiler is a Weil McLain .

    1.What model?

    2.Do you know what operating pressures are?

    Sorry to bombard you with all the questions but with the pictures and some more info, it will help us get a better idea of your system's layout.

    - Rod

  • kevinfaz
    kevinfaz Member Posts: 3
    More Information on the Boiler

    The house is about 3500 Sq. ft., and has 18 radiators on 3 floors.  It was built about 100 years ago, and is not well insulated.

    The bolier is a Weil McLain EG75,  and I have the pressuretrol set at the minnimum setting.

    An additional piece of information:  We learned yesterday that the automatic water feeder was turning on immediately after the boiler cuts off, and perhaps before all of the condensate has returned to the boiler, thus resulting in a water level that is too high.  Not sure if the clanging and spitting could be related to this.  The company that installed the boiler is coming by next week to adjust the timing on the automatic water feeder.

    I certainly don't mind the questions, and appreciate your help.
  • Jamie Hall
    Jamie Hall Member Posts: 19,968

    Near boiler piping doesn't look too bad -- though I'm not really keen on the connection to the equalizer.

    However, high water level in the boiler could definetly cause some, if not all, of your problems.  You may need a time delay on that automatic feeder...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Water Levels

    That's a big boiler and seems a bit big for the house though since they seem to have checked the EDR you're probably okay.

    Two things shut off the burner in normal operation:

    1. Is when the thermostat reaches its set temperature

    2. Is when the steam pressure reaches the upper limit cutoff set on the Pressuretrol

    The burner will also shut off if the boiler water drops below an acceptable (to a dangerous) level. The LWCO (Low Water Cut Off) stops the burner. When the LWCO shuts off the burner (boiler) , it also will activate the automatic watert feeder which will then add water to a pre set boiler water level.

     It sounds that in your case that the boiler' water`level (through steam production) is dropping faster than it can replaced by returning condensate.  When the water level drops too far,`the automatic water feeder ( doing its job) just adds more water so than when the boiler stops its cycle, cools and all the condensate returns you will have the normal amount of water PLUS what ever the automatic feeder`has added.  This results in a higher than normal water line and as Jamie mentioned this is probably causing your problems due to "wet steam"

    I was just looking a few days ago at the installation manual of the Weil McLain EG series as other person on here is having similar problems with an EG-45. You might want to look in the I&O Manual at Page 16. Here's a link to the manual if you don't have your printed copy handy


    It shows a "fix" for the low water problem. I suspect this may be a common problem since they go to the trouble of publishing a "fix".   The boiler manufacturers try to design their systems for minimum wate,r for efficiency  (Heating excess water uses more fuel)  but have no control as to how much a system needs. The bigger the house, the longer the pipes and the slower the condensate return is. Anyway i thought I'd mention it as you might wat to check this out.

    In normal operation water only needs to be added to the boiler every couple of weeks and then only a small amount.  A lot of pros don't really favor automatic water feeders as they can cause problems.   If you develop a water leak in your system, the automatic feeder will refill the system. This constant adding of fresh water quickly corrodes your system. Fresh water contains excess oxygen and this will lead to rapid corrosion of your boiler. It's very important, if you add water to your system, to bring the water to a boil as this drives off the excess oxygen.

    One of the other posters mentioned getting Dan's books, so I'll mention them just in case you aren't familiar` with them.  If you are new to steam you need to get "We Got Steam Heat" 


    and I would also get "The Lost Art of Steam Heating"  You can get them both plus another good book in package.


    They're easy reading and written so a homeowner can understand them. They're humorous and in a few evenings you'll know a lot more about your steam system.

    I constantly recommend them to people as i know they will be as helpful to them as they were for me. The books have paid for themselves probably a hundred times over.

    Since one of the posters mentioned that you only had one boiler riser, I was wondering about this too. Your model boiler I believe has another steam port and while you boiler is piped properly according to the manual, I was wondering why the other port wasn't used. Having a second exit port would half the velocity of the steam exiting the boiler and result in much dryer steam. Your might call Weil McLain and ask about this. If your wet steam problems remain I'd consider adding the second steam riser. One of the problems with these boiler manufacturers is that they specify in theri installation manuals, the minimum piping that can be gotten away with and not the optimum. This i guess is so their unit is competitive in competing for the lowest bid.

    Your boiler setup looks nice. Once you "tweek"it a bit, you will have a comfortable trouble free heating system for the winter.

    - Rod
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