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To reuse or not to reuse....That is the question. :)

Dan's books made it possible for me to install my own boiler into our two pipe steam system, some 20 years ago. That boiler (Weil McClain) cracked a few years back and since then, we've just kept the heat going with space heaters and a gas fireplace. This works on most cool days, but not when the world gets below freezing.

Recently, my mother in law decided to replace her existing older hot water boiler (American Standard G - 25 -DPG), even though the boiler seems to work perfectly. On the boiler plate, it appears that the boiler was designed for both hot water and steam, as the maximum psi for each is listed. As it is, there appears to be only a 2" outlet on the top of the boiler for hot water. But, there may be a larger output for steam underneath the steel cover that isn't currently exposed.

Anyway, to err...boil it down...I was wondering if it would be worth while to replace my cracked boiler with my mother in law's functioning boiler - or, if that isn't advisable due to the age of her boiler, efficiency...etc. The fact that it is free is certainly a bonus. But as you well know, boilers are heavy bastards. So, I don't want to drag this down to my basement if it just isn't worth the trouble.

The square footage of our houses is comparable. So, I'm fairly confident her boiler will provide enough heat. I don't know what all is involved when converting a water boiler to steam. Also, I don't know what to watch out for when starting up pipes and radiators that haven't been in operation for some years

Any tips or help you can give me is much appreciated!


  • Hap_HazzardHap_Hazzard Member Posts: 2,263
    The first thing I'd do is look for an IOM manual for it and see what's really involved in installing it and converting it to steam. It should answer all your questions about how to hook it up and whether you can use the trim from your W-M or not.

    It might not be easy to find one online, but hopefully your mom-in-law saved hers.
    Just another DIYer | King of Prussia, PA

    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • To change a hot water boiler to steam requires all new trim (low water cutoff, pressure controls, etc.), you will spend a lot of money to install a used boiler that may only have a few years left and at best, it would be 80% efficient. To me, it makes no sense to use the old one.
    Often wrong, never in doubt.

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    mattmia2Intplm.AMservicesdelta T
  • EricBSTLEricBSTL Member Posts: 2
    Hap, my MIL just bought the house. So, there's no manual readily apparent. Although, there could be one hidden in the attic somewhere. I'll look online in any case. Thanks for the input. Alan, I'm afraid you might be right. I do have the controls from the old boiler. But, I'm sure there will still be lots of new fittings / adapters to get it all put in place. The difference in cost for a free working boiler and a new one is huge of course. However, I might be better off looking for one that is already set up for steam. A used steam boiler can often be found where I live for anywhere from $100 - 1000.
  • I have some property in Arizona that I'll sell!
    Often wrong, never in doubt.

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  • retiredguyretiredguy Member Posts: 227
    I would never buy a used steam boiler, period. And, if your MIL's boiler was working OK why did she replace it. She must have a lot of cash laying around. As I have stated many times, a hot water boiler can last 100 years or more (I have seen them last that long).When I was still working, a boiler set up for steam carried a 1 year warranty on the sections and that same boiler set up for hot water usually carried a 20 year warranty on the sections
  • Intplm.Intplm. Member Posts: 1,164
    If you want to put the sweat equity into this project? I would do your homework. Think long and hard about this. It's not the best choice first hand. I have never done it and do not know of anyone who has done it with any real success.
    Way your options carefully and best of luck.
  • mikeg2015mikeg2015 Member Posts: 1,178
    After you spend a couple days wrenching on pipe installing a boiler (properly) you’ll realize that you’d rather not repeat all that any time soon and will wish you had just spend the money on a new boiler.

    I just installed a used boiler in my basement. Had to dril and cut out 2 plugs, replace all the damaged refractory, repair the case, and 3 bottles of boiler treatment later it’s finally transferring heat acceptably but I still flush out scale almost daily from the float type LWCO and a low point drain.
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