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New boiler for Mouat vapor system?

The ca. 1922 Ideal boiler (coal to gas conversion) that powers the heating system in the ancestral manse has given up the ghost (unless you can tell me how to effectively repair a 1.5" diameter hole in cast iron where a chronic small leak finally failed catastrophically). It's a fairly large unit (~320,000 BTU, IIRC) with three risers (two for the house, one for the detached garage).

Hole in the boiler notwithstanding, it's a great system that has worked flawlessly for pushing 100 years and I'd like to preserve as much of it as possible, but the local guys all want to convert to steam, with a shoebox-size boiler, associated pumps, loops, etc. I don't want to do that, for any number of reasons.

The basic question is simple: are there any boilers out there that are even close to a drop-in replacement for a vapor system? That is, I realize there will likely be some repiping, but I want to stay away from messing with valves, vents, etc.

Thanks.

Comments

  • JohnNY
    JohnNY Member Posts: 3,293
    Interesting post. Can't this be any steam boiler set up with the right modern controls to meter system pressure?
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
    Consulting & Troubleshooting
    Heating in NYC or NJ.
    Classes
    ethicalpaul
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    What is your location? A real pro can measure your radiators to size, and install an appropriate modern gas steam boiler, and often make it work better than the original one.—NBC
    ethicalpaul
  • Jamie Hall
    Jamie Hall Member Posts: 24,876
    Now I am well and truly puzzled. There is absolutely no reason why any number of modern boilers -- Burnham, Weli-McClain, Peerless, the list goes on -- can't be put in and hooked up to your Mouat (or, for that matter, any other) vapour system. It's purely a matter of determining the correct size boiler -- which is easy -- and installing it properly -- which is also easy, provided you get a contractor who knows something about steam or vapour heat.

    Which, obviously, your local guys do not.

    Where are you located? You can either try "Find a Contractor" on this site, or if you let us know where you are it is quite possible that we know someone who is qualified in your area.

    Whatever you do, don't let your local clown show bamboozle you into converting. Do it right. It will be less expensive and you'll be much happier.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ethicalpaul
  • SeanBeans
    SeanBeans Member Posts: 520
    This sounds like a pretty complicated boiler room and would definately benefit from someone on this forum taking control of your replacement.
  • dopey27177
    dopey27177 Member Posts: 887
    I am retired close to 30 years. Worked on several systems like yours. There is no problem with a new boiler install. Key to the new install the boiler should be a tall one . Not a squat size boiler.

    You need to make sure the water level in the boiler is the same or have the contractor install a false water line (a piping configuration that mimics the old boiler water level.

    There will be some significant changes in the boiler piping. Key to a good working job is how system air is removed.

    I do not know where you live but I am giving you some date to show the contractor on how you need the install to look.

    I don't often recommend contractors unless I know their work. If this contractor works in your area he is a good one to select'

    I wrote a book on steam heating. The false water line is taken out of my book Steam the Perfect fluid for Heating and some of the Problems. Please excuse the hand writing on my drawing as bad arthritis in my hands.

    Available at Dan's library, Barnes and Noble, Amazon and Dorrance Publishing in Pittsburgh Pa.

    Jacob Myron


  • dopey27177
    dopey27177 Member Posts: 887
    My scan of the data for you did take. I am enclosing it on this comment.

    Jacob Myron
  • AdamSwapp
    AdamSwapp Member Posts: 18
    Thanks for the replies.

    For a bit more info:
    - I'm in NE Ohio (near Canton), on the very outer fringes (or perhaps just past the southern edge) of Gerry Gill's territory.
    - Using the table from http://www.smithfieldsupply.com/company_info/forms/radiatorest.pdf for columnar radiators, total EDR for the house is 450; add 200 for the garage. If I've done my measuring, counting, and ciphering correctly, that's 108,000 BTU for the house, plus 48,000 if we keep the garage heat.
    - Current water line is 51.5" above the floor.

    My fundamental position echoes what you guys are saying: a system that's worked for almost 100 years with no moving parts should not now require a complete redesign and all manner of electrical/mechanical/computerized add-ons to function again. Not to oversimplify, but it seems to me that a new boiler and some rejiggered piping should about do it. Am I missing something here?

    Any recommendations for a particular brand/model of boiler? Any to avoid?

    Thanks.
  • Jamie Hall
    Jamie Hall Member Posts: 24,876
    You're not missing a thing. As to what boiler? That depends on what is available -- almost any of the major makes (Burnham, Weil-McClain, Peerless, etc.) are good and reliable. Question is, what are you going to fire it with, and who is going to install -- or help you install it? And what make or makes do local supply houses have?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • AdamSwapp
    AdamSwapp Member Posts: 18
    It will be gas fired.

    I know that Weil-McLain is available locally. Not sure about others.

    Who's going to install it? That's a good question. Hopefully, not me, as I have neither the tools to work with large pipe nor the desire to smash the old boiler into pieces that I can carry out of the basement. I'd like to find someone who is already familiar with this system, as my experience is that it's a less than optimal working relationship for all concerned when the customer is (or has to be) constantly looking over the tradesman's shoulder. That's proving to be a bit of an adventure.

    And about sizing... The Burnham IN6I (110 MBH, 458 sq. ft), Peerless IN6I (108 MBH, 450 sq. ft), and Weil-McLain EG-50 (109 MBH, 454 sq. ft) are sized almost exactly for this load. Is it advisable to go with something like that, or should we step up a size for a little extra capacity?
  • ethicalpaul
    ethicalpaul Member Posts: 6,669
    edited October 2019
    > but the local guys all want to convert to steam, with a shoebox-size boiler, associated pumps, loops, etc. I don't want to do that, for any number of reasons.

    Did you mean to say the local guys want to convert to water?

    NJ Steam Homeowner.
    Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
    See my sight glass boiler videos: https://bit.ly/3sZW1el

  • Jamie Hall
    Jamie Hall Member Posts: 24,876
    On sizing -- you do NOT want to step up a size with steam -- particularly with a vpour system. Your heating capacity is determined by the installed radiation, not the boiler, and the boiler should match that as near as can be.

    If you can find a company or tradesperson who is willing to work with threaded pipe and follow the manufacturer's instructions and perhaps a little help from the Wall, you should be able to get it done. That Well-McClain is a good unit and if it's available locally, that's a real plus. Perhaps the dealer can suggest a suitable tradesperson.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • PMJ
    PMJ Member Posts: 1,266
    A match with the installed EDR will be plenty of boiler. The boiler on my Mouat system is matched that way and I only need about 1/2 of its capacity to heat on design day.

    1926 1000EDR Mouat 2 pipe vapor system,1957 Bryant Boiler 463,000 BTU input, Natural vacuum operation with single solenoid vent, Custom PLC control