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Wet returns rusted and 7" nipple stuck in OLD cast iron boiler - How to remove nipple?

See pics - I've got this old boiler which I'd like to have limp along for another couple of years. - Problem is leaking in wet returns and especially where 7" (approx) nipple goes into boiler. Thought I'd cut the 7 incher at the boiler then try to remove the stub left in the threads, then as backup plan I thought I'd be able to have a welder weld a nipple to a plate and weld that to the boiler. Can't find a welder that would do it.

The plan is to replace both wet return pipes that join into this 7" pipe and the pipe.

Any thought on how to proceed?

Also, if I replace boiler, what, roughly, efficiency would I gain do you think?



  • Todd_33Todd_33 Member Posts: 54
    More pics - sorry about the quality -
  • FredFred Member Posts: 8,418
    edited September 2016
    Is the boiler leaking in other places? I see several places where rust stained water appears to have run down the boiler, opposite those returns that drop to the wet return. Normally I'd say cut that pipe out that goes into the boiler and then carefully take a small manual hack saw and cut through the pipe, being careful not to damage the threads on the boiler, and peel the old pipe away. However, looking closely at your pictures, it looks like the cast iron on the boiler, around that pipe is rusted/broken away as well. I'm thinking it's time for a replacement boiler and probably much of the piping. Those returns that drop down from the dry returns should not rot through (at least not that high up) like that unless they are plugged with sludge and hold water for extended periods of time. You probably can't find a welder to do this job because there is not substantial metal left to weld to and it would turn into a nightmare for the welder.
  • Todd_33Todd_33 Member Posts: 54
    Thanks Fred - the returns were covered w insulation which got wet from leak then did a number on the pipes. - my hope is to replace the return setup completely.

    Haven't noticed other leaks except - had header leak 8 years ago which I more or less fixed. sorta...

    From the looks of it, do you think that pipe would peel out of the opening? I hate to dig into it without a plan B
  • FredFred Member Posts: 8,418
    It all depends on how much rot there is around that area of the boiler Tapping. If it is solid, I suspect you will be able to pretty much pick the rotted pipe out without much effort. If the area around that pipe tapping is also rotted, plan "B" is a replacement boiler. "Expect the best, plan for the worst."
  • Todd_33Todd_33 Member Posts: 54
    Yah - that's what I'm thinking. Still wondering about welding a plate with nipple attached. Or maybe drilling and tapping and fastening a plate that way. Thanks -
  • Jamie HallJamie Hall Member Posts: 12,710
    Well... if you can get the nipple out, and the threads in the boiler are usable at all, you may get by for a bit with a new nipple.

    However, I can't honestly say I recommend welding on a cast iron boiler. Yes, it can be done. No, it isn't easy and it takes real skill -- and a LOT of heat. It's remarkably easy to crack the cast iron...

    How old is that monster? A modern steamer should get you up to 85% or so without any problems, oil or gas, and if that thing is as old as it looks... could be really significant.
    Br. Jamie, osb

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Todd_33Todd_33 Member Posts: 54
    Hi Jamie - Thanks for the comments - Boiler is original to the building, 1929 !
  • I think your savings will be pretty dramatic, and I think everyone got their money's worth out of that boiler.

    If I were you, I would find your contractor and get the replacement all spec'ed out and ready to go asap. Then I would cut into that nipple to remove it and see what I've got. You'll be covered either way.

    If it were me, -I would replace it already. 1929....

    New England SteamWorks
    Service, Installation, & Restoration of Steam Heating Systems
  • LionA29LionA29 Member Posts: 254
    That boiler needs retiring. A more efficient unit will be beneficial than putting time and $$ in that. Just my $0.02
  • RayWohlfarthRayWohlfarth Member Posts: 802
    Yikes, I would be very hesitant to use that boiler. As soon as you touch it, you own it. (Speaking from experience) I would suggest you consider replacing it
    Ray Wohlfarth
    Boiler Lessons
    Click here to take Ray's class.
    Click here to buy Ray's books.
  • FredFred Member Posts: 8,418
    @RayWohlfarth , he already owns it. I think he is the HO.
  • Todd_33Todd_33 Member Posts: 54
    Just putting closure on the thread - Eventually I found a small, 3 person company that would work on it. They were able to remove and replace the rusted returns and even the 5", leaking nipple screwed directly into the cast iron boiler. Apparently, even after 80 years the cast iron threads didn't rust out even though the nipple had. Whew.
  • the_donutthe_donut Member Posts: 374
    Boiler still chugging along then?
  • quack24quack24 Member Posts: 62
    i would call the original installer back and tell him to fix it
  • Todd_33Todd_33 Member Posts: 54
    Yep - boiler still chugging - installed 1929 I believe...! -
    Quack24 - I did exactly that - his receptionist said he was out of town mountain biking in patagonia with his new girlfriend -
  • ethicalpaulethicalpaul Member Posts: 1,572
    1 pipe Utica 112 in Cedar Grove, NJ, coal > oil > NG
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