Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Multiple Steam Boilers

Diar
Diar Member Posts: 50
Hi,

I am getting a new steam boiler setup and am intrigued by the potential saving of a multiple boiler system. I have an EDR of 1300 sq ft (~400,00 BTUs) and am being quoted $25K for a multiple boiler system and $16K for single boiler system.

In what senarios would the cost of a multiple boiler system be worth the extra price?

Thanks,
Diar

Comments

  • Al Letellier_9
    Al Letellier_9 Member Posts: 929
    steam boiler(s)

    I can't see the value of two boilers for that load. I would go with one boiler and use a good staging or cycling control to operate the boiler. You didn't say how the system is set up, so I don't know enough to guess at it, but staging boilers for steam is not like doing it for hot water. Make sure your heat guy knows what he is doing if going with two boilers.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Diar
    Diar Member Posts: 50


    I just can't figure out how much savings a multiple boiler system can provide. I know that you can use a much smaller boiler, so it will be more efficient, but if the gain in effiency of a MBS is < 10% it wouldn't be worth considering.

    I am not sure what you mean by a staging / cycling control. I have looked into lo-hi / lo-hi-lo burners. If this is not what you meant, please let me know. I told that lo-hi / lo-hi-lo burners wouldn't work well on my small setup. I was told that they are generally used on commercial systems that are always running during the winter. I was told that the lo fire would lead to condensation in my small system / was hard to set properly. Do you believe this is this true?

    Thanks,
    Diar
  • gerry gill
    gerry gill Member Posts: 3,032
    hi/lo works very well..

    even in houses since the boiler doesn't know its in a house..vapor systems should be set up this way..

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    gwgillplumbingandheating.com
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Diar
    Diar Member Posts: 50


    What about one-pipe steam?

    - Diar
  • gerry gill
    gerry gill Member Posts: 3,032
    works just fine

    for one pipe also..the boiler doesn't know what radiators are there either..

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    gwgillplumbingandheating.com
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Diar
    Diar Member Posts: 50


    Do you know a hi-lo burner that would work well with my target system, which is a Weil-Mclain 480? I've checked out the Weil-Mclain Model 80 specs, I thought that I'd have to get at least a 580 to be able to use a hi-lo. If this is true, would it be more efficient to get an slightly oversized boiler such as the 580( few hundred more sq ft steam than necessary ) and run it on a hi-lo, instead of getting a 480.

    If I could find a hi-lo burner my boiler, would the burner installation ( burner / outside temp reset / additional controls ) be too expensive to purchase/install given the base price of $15K for the boiler setup already?

    Thanks,
    Diar
  • gerry gill
    gerry gill Member Posts: 3,032
    i'm not familiar with the w-m line,

    as i don't use their product..but with the ones we use, if the don't come the way we want them, then we add the necessary equipment to them..

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
    gwgillplumbingandheating.com
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Multiple Boilers

    Dire;
    I have a multiple steam boiler system up-here that I
    "inherited", to look after. Its not very big either(1440sq.ft). There are 3 of them. It is "extremely" oversized so it is a "pain" to manage. As I`ve never seen any 2 boilers fire "exactly" alike,(let alone 3), this will likely cause problems for you. Piping multiples is very "tricky", and the manufacturers specs are not always right. I would go with 1 on something this small.
    Good Luck!
  • Diar, the 4-80

    is not available with a lo-hi-lo burner right now, because they don't make a lo-hi-lo burner that small. But I expect this will be available at a later date, at which time you could replace the burner and add a Vaporstat to switch between low and high fire.

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Diar
    Diar Member Posts: 50


    There was some debate over whether I should go with a 480 or 580 ( I'm disconnecting the radiators in my attic, since it isn't used, which leads me to a 480 ). Would it be useful to instead choose to go with the larger boiler/580, as some have recommended for a safe sizing match, so that I could get the savings of a lo-hi-lo along with it?

    With that said, I'm not sure if there are any good lo-hi-lo options even for a 580.

    Thanks,
    Diar
  • Boilerpro_5
    Boilerpro_5 Member Posts: 407
    I have a few multiples running now....

    and they work very well. They are the Slantfin units. If you have them put in, they must be piped exactly as Slantfin says. A 360,000 input, 2 180 mods, is firing in a one pipe system for an apartment structure and the 500,000 input, 2 250 mods is firing in a two pipe system feeding air handlers. With the 500,000 unit, I don't think they ever ran both mods last winter, due to internal gains (its retail space). If you plan on adding TRV's to your system, modulars would make alot of sense. On hot water, I usually suggest moldulars for anything over 200,000 input. A hi/low burner would be nice too on a single unit, or a modulating burner.

    Boilerpro

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
This discussion has been closed.