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Conversion of Steam system to Hot water system

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I am now leaning to convert steam system to hot water system. if anyone has personal experience to share about this conversion, would love to hear it.

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  • KC_Jones
    KC_Jones Member Posts: 5,739
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    The first question, possibly for your education, why do you want to do this?
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    CLamb
  • Labenaqui
    Labenaqui Member Posts: 72
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    Our experience has been limited to converting a qualified Steam Boiler to FHW only, not the complete radiator system, if that applies to your situation.
    https://www.boilersondemand.com/steam/converting-a-steam-heating-system-to-hot-water-the-whys-and-hows/
    randers2015
  • AdmiralYoda
    AdmiralYoda Member Posts: 629
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    My first thought is that if you plan to run an atmospheric boiler I'm not sure you will gain anything as both steam and hot water are equally efficient. Second, an atmosphericly vented hot water boiler is going to have an operating temperature of 170-180 degrees so the radiators will be providing less btu's.

    If you plan to use a condensing boiler those run at 140F or less and the radiators will definetely produce less heat.

    You'd need a very good heat loss calculation of your house and rooms to determine if you would satisfy the design temp with the lower btu's of hot water filled radiators.

    Lastly, you'll be going from 1.5psi or less to upwards of 25psi with hot water. Thats a quick way to find out if you have any leaks or areas that were getting ready to leak.

    I'll 2nd @KC_Jones question. Why do you want to do this and what is your goal?
    mattmia2MikeAmann
  • Jamie Hall
    Jamie Hall Member Posts: 23,322
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    There is, admittedly, one more or less valid reason to convert: it's easier to zone hot water than steam. Otherwise, there are hundreds of excellent reasons to not convert.

    Don't do it.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    mattmia2bburd
  • ChrisJ
    ChrisJ Member Posts: 15,702
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    There is, admittedly, one more or less valid reason to convert: it's easier to zone hot water than steam. Otherwise, there are hundreds of excellent reasons to not convert.

    Don't do it.

    I'm going to ask......
    Why is it easier to zone hot water than steam?

    They're both hydronic, what's the big issue?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Long Beach Ed
    Long Beach Ed Member Posts: 1,210
    edited December 2022
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    We've done several conversions, where owners insisted the work be done.

    What would you like to know about the experiences?
    CLamb
  • ethicalpaul
    ethicalpaul Member Posts: 5,704
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    ChrisJ said:

    There is, admittedly, one more or less valid reason to convert: it's easier to zone hot water than steam. Otherwise, there are hundreds of excellent reasons to not convert.

    Don't do it.

    I'm going to ask......
    Why is it easier to zone hot water than steam?

    They're both hydronic, what's the big issue?
    You can have separate actual thermostats for the different zones that actually turn on/off the flow of hot water to those areas rather than messing with balancing steam flow and half measures such as TRVs.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • retiredguy
    retiredguy Member Posts: 906
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    My experience with conversions from steam to hot water was with large commercial buildings including schools and nursing homes. In these instances, and this is according the Building engineer or maintenance supervisor, is that there was a cost savings around 30%. The best explanation was that the savings came in the spring and fall when the system's water temp could be raised just a few degrees to heat the building instead of raising the boiler's temp to 212F and above to produce the steam, and then shutting off the boiler and loosing that sensible and latent heat of the water. Also, it was easier to zone the system for better temp control.
    Long Beach Ed
  • mattmia2
    mattmia2 Member Posts: 9,662
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    don't
  • The Steam Whisperer
    The Steam Whisperer Member Posts: 1,215
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    My experience with conversions from steam to hot water was with large commercial buildings including schools and nursing homes. In these instances, and this is according the Building engineer or maintenance supervisor, is that there was a cost savings around 30%. The best explanation was that the savings came in the spring and fall when the system's water temp could be raised just a few degrees to heat the building instead of raising the boiler's temp to 212F and above to produce the steam, and then shutting off the boiler and loosing that sensible and latent heat of the water. Also, it was easier to zone the system for better temp control.

    The big question that always come up is "What was the condition of the steam system before being converted?" Was it even in somewhat decent condition? The steam systems we have "converted" to modern steam systems easily produce 25 to 30% fuel savings, some around 50% when upgrading to outdoor reset modulating power burners. We haven't even touched condensing steam boiler technology yet in these systems, which would probably get another 5 to 7% improvement.

    I am hoping in the next couple years to do a back to back comparison of steam to hot water using the same boiler, system and building in my own home.
    To learn more about this professional, click here to visit their ad in Find A Contractor.
    mattmia2bburdNew England SteamWorks
  • randers2015
    randers2015 Member Posts: 14
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    Thanks. Here is the situation: to get an erngy star boiler since there is no known energy star STEAM boiler. There is Hot Water boiler but not steam'

    The current steam boiler cannot be repaired; i have to get a new one so, i want to get an energy start boiler and this is what I have been thinking about.

    No this is a home and not commercial building.
  • mattmia2
    mattmia2 Member Posts: 9,662
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    You're going to spend way more trying to convert the system than you will ever save in fuel. get a properly sized steam boiler and fix any issues with the steam system.
    ethicalpaulLong Beach Ed
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,844
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    Since an energy star boiler will qualify for a one time rebate of $$$ and the higher efficiency will yield an annual savings of $$ for a total 20 year savings of $$$$.

    Now compare this to the $$$$$ cost of the conversion. Will it be worth wile?

    If you want an energy star appliance, you should just get a furnace with ductwork. That way, you can get central air conditioning at the same time.

    Or you can get a price on a new steam boiler from someone in the FIND A CONTRACTOR link above.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    randers2015
  • Steamhead
    Steamhead Member Posts: 16,842
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    Thanks. Here is the situation: to get an erngy star boiler since there is no known energy star STEAM boiler. There is Hot Water boiler but not steam'

    The current steam boiler cannot be repaired; i have to get a new one so, i want to get an energy start boiler and this is what I have been thinking about.

    No this is a home and not commercial building.

    Not worth it. Keep the steam. You will never get any appreciable return on the huge investment it would take. Not to mention (because others already did) the potential pitfalls.

    This subject comes up every so often. Here's one thread where someone tried to justify a conversion, which effort fell flat on its face:

    https://forum.heatinghelp.com/discussion/145002/actual-savings-over-steam-heating

    The Burnham MegaSteam series was EnergyStar rated until recently.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • pedmec
    pedmec Member Posts: 975
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    Do what i do. Build your manifold on your new wall as if your piping in mod/con and pipe it primary/secondary. Do a horseshoe manifold. Put the expansion tank, air separator, and feed valve on the new horseshoe manifold. install closely space tees. convert the steam boiler to hot water and tie the supply and return with circulator to the closely spaces tee's. now your when you want to buy the mod/con boiler you can just plug it into the existing set-up. no costly changes as you built everything on the wall.

    It doesn't cost much to convert the remaining steam to hot water. just an aquastat, relay, relief valve, some gauge changes. And of course an electrician. you just got to be committed to the new boiler at some point because your setting it up for mod/con. More involved than just building the manifold right out of the cast iron boiler.
    randers2015GGross
  • Big Ed_4
    Big Ed_4 Member Posts: 2,785
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    Post several photos of differant sides of the boiler

    There was an error rendering this rich post.

  • Steamhead
    Steamhead Member Posts: 16,842
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    In this thread-

    https://forum.heatinghelp.com/discussion/190331/size-of-team-boiler-for-2300-sqft-house-3-floors-contractor-said-86-000-output-is-sufficient

    the OP says this is one-pipe steam. That means running all new return lines- and the radiators themselves may not work with hot-water at all. Then there are the other pitfalls.

    @Jamie Hall et al, you're right.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    randers2015
  • Long Beach Ed
    Long Beach Ed Member Posts: 1,210
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    If the socialists in your municipality will not permit anything but an EnergyStar boiler, buy a sticker on ebay and put it on a new steam boiler. The entire program is a money-sucking scam and you'll be the loser if you fall for it.
    MaxMercyMikeAmannranders2015
  • AdmiralYoda
    AdmiralYoda Member Posts: 629
    edited December 2022
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    If you are being forced to only buy an Energy Star boiler.... sounds like it would be cheaper and easier to just replace the entire heating system with forced hot water baseboard or similar.

    If this a personal decision or a decision based on a rebate.... a new steam boiler will still be significantly cheaper and easier to install than the hot water alternative. By the time the efficiency savings make the payoff worth it...it will be time for a new boiler anyways.
    randers2015
  • randers2015
    randers2015 Member Posts: 14
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    Thank you ALLL. All points are well taken. Appreciate the expertise and will stick with a new steam boiler system. May consider a split system in the future for the AC. We are using just window AC if we use that and lovely ceiling fans.
  • AdmiralYoda
    AdmiralYoda Member Posts: 629
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    @randers2015 Out of curiosity, have you had problems with your existing one-pipe steam system?

    More often than not modifications and alterations to piping have been made over the years by less than competent "experts". Usually resulting in grossly oversized boilers and poor piping and venting. Perhaps post pictures of your near boiler piping for the pro's here to critique along with your main venting setup.
    Do you know the EDR of your existing radiators and the steam capacity of your existing boiler?

    A properly sized, piped and vented boiler can provide significant savings over an oversized poorly piped mess. Non-condensing atmospheric boilers for steam or hot water are about equally efficient. So you may still have the opportunity to be roughly as efficient as a hot water system but without spending the big $$$ to convert it and sticking with steam.
    randers2015
  • randers2015
    randers2015 Member Posts: 14
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    The system is broken and done with.


  • randers2015
    randers2015 Member Posts: 14
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  • Jamie Hall
    Jamie Hall Member Posts: 23,322
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    Well, it is an old boiler for sure. But sizing and putting a new one in to replace it would be no difficulty at all for a good steam man.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    randers2015ethicalpaul
  • Jamie Hall
    Jamie Hall Member Posts: 23,322
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    as I said in the other thread -- it should be no problem to put a new, properly sized boiler in there. If there aren't other problems it's an easy job.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ethicalpaulbburd
  • mattmia2
    mattmia2 Member Posts: 9,662
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    That rollout likely isn't a problem that is the fault of the boiler. Whatever issue caused that will have to be addressed whatever is put in there.
    bburdranders2015
  • ChrisJ
    ChrisJ Member Posts: 15,702
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    Those aren't pictures of the heating system, that's only the boiler.

    The radiators and piping would cost a small fortune to have installed and are a big part of the system.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    randers2015
  • ethicalpaul
    ethicalpaul Member Posts: 5,704
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    That's one broke-down, rusty-butt, beyond its expiration date, paid for itself 3x boiler, but that's not Steam's fault
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • ethicalpaul
    ethicalpaul Member Posts: 5,704
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    Or woman
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    bburdmattmia2Long Beach Ed
  • bburd
    bburd Member Posts: 917
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    Insulating the steam pipes will go a long way toward improving fuel efficiency and the speed with which the system heats. There are many threads here on this subject. 1 inch fiberglass is the material of choice, not usually available at big box stores, but it can be ordered online. It’s a relatively easy DIY project.

    Bburd
  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 2,287
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    I've merged all duplicate posts on this here. Thanks @ethicalpaul.
    President
    HeatingHelp.com
    Long Beach Edethicalpaul
  • jumper
    jumper Member Posts: 2,259
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    My experience with conversions from steam to hot water was with large commercial buildings including schools and nursing homes. In these instances, and this is according the Building engineer or maintenance supervisor, is that there was a cost savings around 30%. The best explanation was that the savings came in the spring and fall when the system's water temp could be raised just a few degrees to heat the building instead of raising the boiler's temp to 212F and above to produce the steam, and then shutting off the boiler and loosing that sensible and latent heat of the water. Also, it was easier to zone the system for better temp control.

    Certainly easier and less expensive to convert to vacuum steam heat for spring & fall.
    Long Beach Ed
  • randers2015
    randers2015 Member Posts: 14
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    Thank you everyone for your input!!!!. I will keep steam. I have found an excellent contractor that actually seem to be reasonable and had some similar points here about keeping stem, and not worth the conversion. Looking to have the work done in the next couple of months!
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,540
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    @randers2015

    Just make sure before your contractor starts there are several key points that if missed ......well you will be sorry.

    Make sure

    He measures radiators this is the ONLY way to size a steam boiler
    that he pipes the boiler in accordance with the install manual
    Uses all black pipe for the steam,,,,copper allowed on the return lines below the boiler water line
    that he skims and cleans the boiler after the install
    Long Beach Ed