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Boiler seal leaking...

Hello, I have a Dunkirk PS841 gas/steam boiler. It is about 15 years old. It has been leaking (I have to fill it every day and there is water on the floor...slow-ish leak). I had a guy come in and look at it and he said the seal (at the bottom of the cast iron tank) is leaking. The only option is to replace the whole furnace. Is this true? No way to replace the seal?


  • Joe V_2
    Joe V_2 Member Posts: 234
    get a second opinion.

    And a third. 15 years on a boiler is not much time and in my experience, most seals and cracks can be repaired. However, labor to repair may make it un-economical to repair. It may be equal to or more than the cost of a new boiler. The thing is, if you replace one seal, you have to replace all of them and you are paying for an overhaul. This isnt a big deal, but what happens if the boiler leaks again from somewhere else this heating season? Are you going to expect the guy to repair that as well on his own dime? Would you be happy to pay for a second rebuild yourself?

    It is unfortunate that you have to deal with this in the middle of winter, but if it is "slowish", you have nothing to lose by asking others for an estimate to repair and one to replace.

    also, see if you can determine what caused the leak in the first place. Good luck!
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849

    First, the description of the problem shows a lack of understanding of how steam boilers in general, and Dunkirk PSB boilers in particular, are constructed.

    Cast iron boilers are made up of sections, like the one shown on the second page of this brochure: http://www.ecrinternational.com/secure/upload/document/1633.pdf (I'm not sure if this is exactly the same as the sections in your boiler, but it's the closest I could find.) Some manufacturers use rubber gaskets between the sections, but, as this brochure shows, Dunkirk uses push nipples.

    It's possible for push nipples to leak too, so maybe this is what he meant, but it's possible to replace push nipples and gaskets. It's not always worth doing, depending on why it failed.

    So there's no clear answer to your question, and based on what you've been told, there's plenty of reason to question the verdict.

    You should try to find an experienced steam professional to take a second look. He might tell you the same thing--that you need a new boiler--but at least he can explain the problem more accurately and why it isn't cost-effective to repair it, and you will have found someone qualified to install your new boiler.

    Where are you located?
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • fishstick_kitty
    fishstick_kitty Member Posts: 2

    That brochure looks very close to my unit. I am in Portland, ME. Right now I can limp by with a daily refill. He showed me where it was leaking from...but I didn't really know what I was looking at...the brochure pics help a lot actually...thanks for that.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,849
    Can you post some pictures?

    It might help if you could post some pictures showing where the leak is.

    There is a contractor listed near you in Biddleford.


    I haven't seen his steam work, but you could ask him about it.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • vaporvac
    vaporvac Member Posts: 1,520

    This fellow used to be listed so I hope it's OK to post his info. Rod also lives in Maine. If you strike out with these two , let me know and I'll enquire if my Dad's HW guy works on steam. He lives on Sabbathday Lake.  Colleen

    Steam Pro near Portland,ME

    Hi-   Steam Pros in Maine are hard to find. The closest one I know to you is:

    Ken Viger

    K&J Heating, Inc

    168 Lewiston Rd

    Gray, ME


    (207) 415-0873

     Other people from the Wall have used him and have been very satisfied.

    - Rod


    Two-pipe Trane vaporvacuum system; 1466 edr
    Twinned, staged Slantfin TR50s piped into 4" header with Riello G400 burners; 240K lead, 200K lag Btus. Controlled by Taco Relay and Honeywell RTH6580WF
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