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replacing steam boiler, need advice

First I want to thank all the experts on this site because I've been learning a lot from these forums. I'm a new homeowner and last week received three quotes to replace the steam boiler (one pipe system) in my 1925 house. The boiler is leaking and needs to be replaced. I don't know who installed it originally. Two of the quotes came from guys who saw my system (let's call them "A" and "B"), and one from someone who has only seen photos (let's call him "C," photos are shared with this post as well). All three are professional plumbers and steam heating specialists and agree a replacement is my only option. I would be extremely grateful to hear what others think, as the difference in quotes is substantial. I also need to replace my garage roof, but the finances don't work if I spend all the money on the boiler. Yay homeownership.

So, the short question is: how would you approach replacing the boiler as depicted here?

A and C quoted much less than B. A is the plumber who I've used several times since I bought my house--he serviced/cleaned the system, fixed a small gas leak, and replaced the automatic water feed and the copper lines going in/out of it. B seems more knowledgeable and is older than A. A, B, and C come recommended by many people on local Facebook groups. A has been reliable and doesn't seem like a shyster. At this point I'm thinking I need to call C and ask him if his quote includes new piping as well.

I asked A to walk me through the differences between his quote and B's quote. A indicated that he didn't believe the pipes needed to be replaced as proposed by B, and that his plan was to swamp out the current boiler, a Utica PEG 112CDE, with a slightly smaller Utica model with a 110k BTU input, for which the existing piping configuration would work. He thought that the level at which the current pipes go in/out of the boiler was within the margin necessary for optimal/correct installation.

B would install a Williamson GSA-125, replace the piping, and measured all my rads to generate the quote. A and C know the square footage of my house (1360) and that I have seven radiators, although they don't have rad measurements like B. C quoted for the same Williamson model as B. A also agreed not to markup the cost of the boiler, so I'm getting a bit of a discount there too. He's really trying to help me out on cost, which I greatly appreciate.

However, I'm wondering if I would be making a huge mistake and pay for it later if I don't insist on having the piping replaced, as I believe there is copper above the water line (see photos). I don't want to risk ruining my new boiler by not replacing the piping, but if the risk is pretty low that something will go horribly wrong or that the life of my boiler will be shortened by 10 years or more because of the existing piping, then I would rather go with a lower quote so I can afford fix my garage too.

I don't mind taking a small risk or not doing things completely by the book, but because I'm so new at this and still learning, it's impossible for me to determine what exactly I'm risking and how big of a risk I would be taking to not replace the pipes. What's the worst that could go wrong? All advice greatly appreciated! I know that B is on these forums sometimes, so if you read this, thank you for such a thorough and expert quote!


  • Jamie Hall
    Jamie Hall Member Posts: 23,324
    Let's start off with the basics: the two who didn't actually go around and determine what the installed radiation added up to -- called the EDR or square feet of steam -- really don't know what size boiler is needed. That makes me vary wary of them. C seems to have lucked out on the size of the boiler -- but I take it he is not replacing the near boiler piping? Or is he?

    Now. There is another problem. To really do the job correctly, the near boiler piping -- the pipes right around the boiler and connecting to your steam mains -- are copper, and really should all be replaced with threaded iron piping, installed to the manufacturer's instructions. What is there really isn't right -- there's no proper header, for starters. If there were a proper header, I might be inclined to say to compromise, but as it is, even though I do appreciate your concern for your budget, I think you would -- in the long run -- be much happier to have all that copper replaced.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • bburd
    bburd Member Posts: 917
    edited March 2022
    @ElizabethS You would be well advised to follow @Jamie Hall’s advice above. He is one of our wisest and most experienced members.

    The problem with using copper for steam piping is that it expands much more than iron or steel when heated. This can result in premature failure of the boiler by putting stress on the cast iron sections— which are strong, but brittle —and causing cracks. Avoiding stress on the boiler sections is also why swing joints in the header connections are required by boiler manufacturers.

    The biggest problem we see on this board is boilers installed by people who didn’t follow the manufacturer’s minimum piping requirements, which are right in the installation manual. I suggest you get this written into the contract.

  • KC_Jones
    KC_Jones Member Posts: 5,739
    I wouldn't even trust the one that measured. I had people measure all mine and still size it wrong. They all seem to be working from the plate on the existing boiler.

    Calculating the proper size is easy and we can walk you through the process if you'd like. That way you have peace of mind that things are on the up and up. They may be right, but for me it's always good to check. I would strongly advise you do this.

    If you are interested, start here:

    Ask any questions about anything you get stuck on.

    I agree with the above, I don't see anything correct with your current piping, not just the copper, but the arrangement is wrong, so anyone that doesn't recognize that doesn't know what they are looking at, what else will they do wrong?

    Here are the risks of not piping it correctly
    1. Warranty is technically void, most have verbiage about proper piping and install being a requirement.
    2. It might not run correctly, or not optimally, or it might run fine, or it might fail early....its a huge list of maybes, that for me, wouldn't risk.
    3. Failing of the copper joints, we've seen this plenty on this site.
    4. While not a risk it's reality. You are proposing to pay someone your good hard earned money to do their job completely wrong. For me that's a hard no. Why should I support someone being a hack? Yes, that's a harsh reality here.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • WMno57
    WMno57 Member Posts: 1,280
    Replace the garage roof now. Put off the boiler until late summer or early fall.
    Spring rain will further damage your garage. You can live without heat until late fall. This gives you more time to find a Steam Pro who will do it right.
    Is B proposing to replace the near boiler piping with iron pipe?
    I DIY.
  • Ironman
    Ironman Member Posts: 7,376
    Improper near boiler piping and incorrect sizing are two of the most common (and unnecessary) problems with steam boiler replacements.

    You’ve been given some really solid advice already. Have you tried the contractor locator above?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • ethicalpaul
    ethicalpaul Member Posts: 5,704
    edited March 2022
    The order is wrong. Don't accept any quote until they size your radiation first and THEN decide which boiler to use, and send that info here and we'll tell you how it sounds.

    insist on iron pipes above the water line. Your boiler is small enough that they can use 2". It's so easy, even I did it. Surely a professional HVAC technician can handle it.

    See this thread and so many others for what happens if you trust and don't verify.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • nde
    nde Member Posts: 86
    Where is the leak did anybody show you? Obviously the site glass has been leaking for some time but that is easily fixed and does not require a new boiler.
  • ElizabethS
    ElizabethS Member Posts: 2
    Thanks to everyone for their comments and suggestions! I am getting additional quotes and using the Weil-McClain manual to check on the correct boiler sizing. The leak is coming from the back left side of the boiler when you're facing it from the front. A significant amount of steam is visibly leaking from this area when the boiler fires. There was also water leaking from the bottom of the back left side, but this has stopped since the steam started leaking from the top of the boiler.
    STEAM DOCTOR Member Posts: 1,973
    @ElizabethS. Absolutely need to measure radiation. Absolutely need to redo piping above boiler. Absolutely no copper on steam piping. Saving money now, can cost you big time in the future. 
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 1,007
    While it is true copper expands more than iron pipe (carbon steel), in a 4 foot length heating them from room temperature (70F) to around boiling (220F), the difference is

    Copper thermal expansion = 0.0000093 in/in per degree F
    Iron pipe thermal expansion = 0.0000065 in/in per degree F

    Copper = 0.0000093 x 48 x 150 = 0.0669 in, slightly more than 1/16th in.
    Steel = 0.0000065 x 48 x 150 = 0.0468 in, slightly more than 1/32nd in.

    Or the difference is 0.02016 in. (less than a 32nd) in the expansion between the two materials in those conditions.

    In the first few feet with elbows, etc., I don’t believe it makes much difference, but yes, on long lengths there is a greater difference.

    All that being said, lousy workmanship installing copper voids any mathematical justification of mine.

    I have no complaint about iron pipe; just find blaming failure in short lengths on thermal expansion is a stretch of my imagination.

    For near boiler piping the layout is what is important.

    The professional pipe jobs on HH are great looking (until they get hidden in insulation).
  • mattmia2
    mattmia2 Member Posts: 9,670
    @Erin Holohan Haskell can we add Dan saying "gosh" to the emoji?
    Erin Holohan Haskell
  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 2,293
    @mattmia2, we'll get to work on that. :D