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Amateur DIY hot water boiler install on old gravity system with steam boiler attached (long story..)

gchrisman
gchrisman Member Posts: 21
After last years heating saga at my house (details and photos here: https://forum.heatinghelp.com/discussion/185457/trying-to-understand-old-two-pipe-steam-system/p1), I am entering summer with no changes to the heating system from last year. Over the winter, the (completely incorrect) steam boiler barely kept things from freezing, at spectacular cost in propane. I had two separate contractors come out, look things over, and say they would get back to me with quotes - months have gone by, I've bugged them many times, and no quotes are forthcoming. One guy finally said that he just didn't have time for my job, and the other won't answer my calls or emails at all. Between the original debacle and this sort of apathy, I am giving up on getting any help from the professionals in my area. I need this system to work by next winter, and I think the only way to do it is going to be to do it myself.

I'm a fairly handy guy, but have no experience working with boilers. I've read the long FAQ here about gravity system conversions, and I'm trying to work out the basics: what do I need for parts? Essentially, after I tear out the steam boiler and its parts, it seems like I need:
  1. A new hot water boiler, probably direct vented and around 110k output btus (I've tried to do some heat loss calculations, but there are a lot of unknowns with this house - this seems like a worst-case size for the house and I do plan to add a lot of attic insulation this summer)
  2. Expansion tank sized to the new boiler (not sure how to size this)
  3. Two circulating pumps (the house is piped with two 'zones', one the east side and the other the west side)
  4. A relay for the pumps
  5. Smaller diameter black piping and adapters to connect everything to those big herkin flanges at the end of the original large piping
  6. Vent piping for the new boiler
  7. New valves for the radiators with stuck valves (pretty much all of them)
Am I missing anything? Can anyone offer me any support/suggestions/encouragement? Any ideas about what boiler would be best/easiest for my situation? Good parts suppliers who can help DIYers like myself?

Comments

  • JakeCK
    JakeCK Member Posts: 688
    edited June 17
    So you are going to convert from steam to hot water? That is quite an undertaking for someone who has no experience with this kind of work and is struggling to even figure out the heat loss.

    Edit: n/m, just now read it. **** is that thing :s?  Yea those rads are for hot water not steam. 
  • gchrisman
    gchrisman Member Posts: 21
    No, this was a gravity hot water system, which an incompetent contractor installed a steam boiler on. I'm going to be removing that and installing something that will be more appropriate.
    JakeCK
  • Jamie Hall
    Jamie Hall Member Posts: 18,909
    Since it was gravity hot water before it isn't really all that bad. The gotchas -- which you may already be aware of -- come in balancing the flow to the various radiators to get the heat you want from them. That can be handled by your new radiator valves, although if there are distinct "upstairs" and "downstairs" pipes in each zone, you might add balancing valves on them.

    Individual thoughts -- Item 1; double check your size, if you can. You don't want it too small -- but you don't want it too large, either. I would go with a pretty simple boiler. Fancy mod/cons are wonderful gadgets, but are tricky to get set up right -- even for the folks who do it all the time.

    Item 2. I believe Amtrol has a tank sizing facility. The size they recommend will be too small, since you have the big pipes, so go up at least one size. There are accessories which usually sort of go along with the tank. Air removal gadget, and pressure reducing valve.

    Item 3. You could use two pumps. You could also use one pump and zone valves.

    Item 4. If you were to use one pump, the end switches on the zone valves could be used both to energize the pump and ask the boiler to turn on. You'll need an aquastat on the boiler to manage its temperature. Otherwise, yes you will need a relay -- Taco, among others, makes a nice line of controllers.

    Item 5. Unless you are really happy threading pipe, how are you at soldering copper? Usually easier to do. And quite satisfactory.

    Item 6. That depends on the boiler. The install manual will have pretty complete directions, but that is an aspect which your building inspector or fire marshal should also be contacted.

    Item 7. Yup. Make sure they match, though.

    On the whole, I'd say to go for it. It's not a one day job, and you will hit things which you have trouble with. When you do, get back on The Wall and we'll see what we can do.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    gchrisman
  • jhewings
    jhewings Member Posts: 82
    On the other thread Steamhead pointed out your boiler can work for hot water. It will still be a lot of work to re-pipe and change the controls but maybe you don't need to replace the boiler.
    bburdmattmia2
  • gchrisman
    gchrisman Member Posts: 21
    I looked at converting the boiler, but the manufacturer won't sell me the parts, and it would still be way too large for the needs of the house (by everyone's estimate).
  • hot_rod
    hot_rod Member Posts: 16,278
    A large volume system like that could be ideal for a mod con
    Start with a load calculation
    Consider any past or future building upgrades to get the load as low as possible
    A radiator assessment to see what they are capable of at lower water temperatures.

    Download Idronics 25 for some formulas and ideas.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    mattmia2
  • Jamie Hall
    Jamie Hall Member Posts: 18,909
    The only reason I'm a little wary of a mod/con -- which as @hot_rod said would otherwise be ideal -- is getting it set up properly.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • hot_rod
    hot_rod Member Posts: 16,278
    The only reason I'm a little wary of a mod/con -- which as @hot_rod said would otherwise be ideal -- is getting it set up properly.
    Correct, you must have someone with the  tool and knowledge to setup the burner. An accurate combustion analyzer with the ability to use it
    In some rare cases the burner needs to be set outside the specs in the manual. Knowing when and how to tweak optimum even reliable performance is best left to the trained pro.

    piping, running stat wire can be done successfully by a technically handy person. 


    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • 109A_5
    109A_5 Member Posts: 122
    @gchrisman, If I was in your situation (I read your older post, what a blunder);

    Plan 'A'. DIY a new boiler install (if funding and Boiler availability is not an issue) a correctly sized boiler for the home with all the appropriate recommendations above. Find a boiler you like and down load the manual and read it ahead of time. Learn all you can about these systems, many resources out there, be the expert (at least with what is in your home). Some issues or questions may be worked out before you even get the new boiler.

    I would have a plan 'B' (which is not another cold winter in your home) in case of funding issues or the boiler you want is currently not available.

    Plan 'B'. That existing boiler should certainly keep that house warm and comfortable. However probably not quite as efficiently as a properly sized unit. Download the installation manual for the 'like' hot water boiler, strip off the Steam boiler trim and build it out as a hot water two zone system, since it looks like there is a natural split (unless that makes no sense with the house layout or you are not interested). That work if done correctly the first time could be reused if the boiler is later replaced.

    Things to do over the summer with either plan. Verify good flow through both pipes of each radiator and proper valve operation (harder to repair when the system is in operation). Air bleed valves all work correctly. Insulate the pipes unless you want the heat in the basement.

    A high tech Boiler ? Your choice, My opinion, for me, no way. I like low maintenance costs and higher reliability, and yes I understand I am paying for that with less efficiency. I'd rather have heat when I need it.

    I'm glad that carpet ? is gone that was in the picture in front of the older boiler. It looked liked like a fire hazard !!!
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 11,987
    @gchrisman Did you try "find acontractor" on this site?? Where are you located? Someone may have a recommendation.
  • retiredguy
    retiredguy Member Posts: 606
    edited June 18
    I am not going to add my ideas to this thread since you guys seem to have the problems "well in hand". So, correct me if I am wrong; converting a steam boiler to hot water is not that hard. You remove the steam trim and add aquastats and a few necessary controls. As for the gravity system, why not just repipe the piping at the boiler for hot water and add a very small circulating pump. It can't be that hard. Am I missing something?
    mattmia2
  • gchrisman
    gchrisman Member Posts: 21
    Thanks, everyone, for the good advice and ideas. I think my first project is to complete a heat loss calculation, with whatever measurements I need to take - it seems that is the most important thing at this stage. From there, I'll investigate my boiler options. Because of my inexperience, I probably will stick to the simpler boilers, but I'll read some manuals to make sure I know what the options are. In the meantime, I'll replace valves and make sure the old pipes are open. I'll keep this thread updated, and will definitely ask more questions as they come up!
  • PC7060
    PC7060 Member Posts: 709
    @gchrisman Where are you located? 
    Location would be helpful. 
  • pedmec
    pedmec Member Posts: 191
    Sorry to hear about your boiler. But i have to say i'm shocked. I cant believe what i'm seeing. I truly believe that the installer is not a heating contractor, most likely a handyman. i don't believe there is any legitimate plumber/hvac contractor that wouldn't know the difference. the funny part is he didn't even pipe the steam boiler correctly either. lol.

    Good thing for you is you can convert that steam boiler to a forced hot water boiler fairly easy. So the boiler doesn't have to get trashed. But please get references next time. don't attempt this yourself. It should be fairly cut and dry for a reputable contractor to fix correctly.
  • gchrisman
    gchrisman Member Posts: 21
    For location, I am in a tiny town in south-central Iowa, with very few good contractors around. I have had similar trouble getting help with plumbing (or anything else for that matter). I moved here recently to fix this house up, and have been shocked at how difficult it is to get any real professional help. The ones in larger cities are busy in their own area and don't want to travel out into the country (especially for difficult and complicated projects, it seems). So, I've been learning a lot about doing various things myself...

    I took a lot of measurements over the last few days and crunched the numbers for the heat loss calculation, making a few assumptions about the R-value of the walls and foundation. The house was built in 1908 and has had very few updates. The house has a full basement with 24" thick limestone walls and concrete slab, unheated except for the large pipes of the gravity system. I ran the calculations taking into account the insulation I'll be adding to the attic later this summer, and the storm windows I'll be replacing as well. What I came up with was a required BTU output of 90,100 at the low end (assuming R-6 for the walls, which are thick wooden siding, dimensional lumber, newsprint 'insulation', and original limestone plaster & lath) or 100,300 at the high end (assuming R-4 for the same walls). This means that the existing boiler is hugely oversized, besides being set up for steam.

    I've been looking online at some boiler options, but does anyone have any suggestions of particular models or brands given my needs?
  • hot_rod
    hot_rod Member Posts: 16,278
    You need to decide if a basic cast iron boiler is the best option, or a mod con. Both will have OEM electronics that can fail and put the system down. It may come down to availability regardless of thew type or brand.

    I've done trainings at a distributor in Fargo and a handful of the plumbers were still converting new cast boilers to standing pilot for their remote installs :) That is about as simple and trouble-free as you can build a boiler. Probably not a factory authorized conversion however.

    That same branch had 15 year old Munchkins heating their own building, last I was there.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • 109A_5
    109A_5 Member Posts: 122
    hot_rod said:

    That same branch had 15 year old Munchkins heating their own building, last I was there.

    I smell redundancy here.

    I really like my thermocouple changes (can't remember the last time, I have spares, and inexpensive) and the fact I can run my boiler from a battery. Maybe a dying art (or technology) but it keeps me warm during a power failure, and I probably don't miss the many $100 or $1000 repair bills. I do consider my self lucky to have old school steam heat. If I had Hot-Water heat I probably would have a Plan 'B' low DC Voltage circulation pump.

    I seem to read a lot more about expensive high tech disasters on this site than 'how do I change my thermocouple'. Some folks get lucky and change a sensor themselves. To each His/ Her own I guess.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • 109A_5
    109A_5 Member Posts: 122
    gchrisman said:

    I've been looking online at some boiler options, but does anyone have any suggestions of particular models or brands given my needs?

    With the present supply chain issues you may want to see what is actually available in the BTU size you desire, then make a choice of actual available units.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System