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Removing 42 Year Old 2-1/2" Unused Return Fitting on Boiler?

Hello again guys. I have a 42 year old Peerless boiler, two generations older than todays 63-03 equivalent. The boiler has two 2-1/2" return fittings on each side of the rear bottom of the boiler. The one on the left side is unused and has a plug installed.

I've been thinking of removing this plug to have access to wand the boiler out and also as the return for a small hot water loop for the basement.

I have a 1/2" drive square socket that will fit and a 3ft breaker bar and some old pipe to use as a cheater. How bad of an idea will it be to try and crack this loose? Am I asking for trouble?

I could heat it up with a torch to try and break down any rust on the threads...but I really don't want to damage the threads or worse crack the boiler casing. Thoughts?


  • Jamie Hall
    Jamie Hall Member Posts: 23,276
    Well, wanding to clean a boiler is a nice thing to do. But. Considering the odds of breaking something while trying to extract a plug which has been there for 42 years, I wouldn't do it. You might get lucky -- some people win the lottery, after all -- but there's a good chance that something like the boiler itself could be damaged. Not worth it, in my view.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    IronmanLong Beach Ed
    JUGHNE Member Posts: 11,060
    Why not put a full size tee with nipple/cap on the existing open port?
  • Ironman
    Ironman Member Posts: 7,375
    The boiler is past normal life expectancy. If you’re prepared to replace it, have at it.

    By “prepared”, I mean that you have a new boiler and the necessary materials on hand and that you’re able to go without heat for a few days. Otherwise, I’d leave it alone.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • AdmiralYoda
    AdmiralYoda Member Posts: 627
    Yeah I think I'm going to leave it be lol.  The hot water loop isn't worth the risk, just a nice to have.   Wearing a sweatshirt while I'm in the basement is alot cheaper than a new boiler.
  • Waher
    Waher Member Posts: 250
    It's best to do any risky tinkering outside the heating season so that if something fails bigly it isn't catastrophic.
    Long Beach Ed
  • WMno57
    WMno57 Member Posts: 1,264
    I wouldn't touch it until heating season is over. In the spring, a MAPP gas or Oxy Acetylene torch would probably break the rust bonds. You would need to completely drain the boiler. Otherwise the water would carry away the heat. Propane will not get hot enough. There is some risk that you wreck a working boiler. Got to break a few eggs to make an omelet.
    I DIY.
  • Chris_L
    Chris_L Member Posts: 336
    If your boiler has an MM67 float type low water cut-out, I am not sure how much more you'd get out by wanding.

    I have a 35+ year old Burnham boiler with the drain valve in one of the return fittings. Even when I get a lot of gunk out of the LWCO during a blowdown, I get very little out by blowing down that drain.

    The one time I removed the drain valve and the return on the other side to flush out the boiler, I didn't get much out either. I concluded that flushing the LWCO, the bottom of which is lower than the return fitting, was good enough.
    Long Beach Ed
    EBEBRATT-Ed Member Posts: 15,517
    You could leave the plug in and drill and tap it for 1/2 or 3/4 " pipe to get your loop and wand access.

    Or you can try and wrench the plug out with moderate pressure. If it doesn't move you can drill a hole in the plug and cut it out
  • Long Beach Ed
    Long Beach Ed Member Posts: 1,202
    Leave the old girl alone. The mung may be plugging leaks. Wait till off-season and drain it, refill it and boil off the air.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    First, those are 2", not 2½" tappings.

    Second, applying heat won't help at all, because you have to make the casting expand faster than the plug, and cast iron conducts heat pretty well, so it's not going to happen. The thing that makes it so hard to remove these plugs isn't rust, it's the 40-year-old thread sealant that's on the threads. Contrary to popular belief, impact is not effective in breaking these joints. Standing on the end of your pipe for a few minutes will do more good than jumping up and down, and won't be as likely to crack the plug. If it doesn't yield, get a friend or a longer pipe, but at some point you need to decide if you want to tempt your fate.

    My Peerless is about as old as yours, and the last time I tried to remove a plug, the the square lug broke right off. Fortunately it didn't leave a hole, but it might be different with a 2" plug. The one I broke was only ½".

    I used the pressure gauge tapping to wand my boiler, and I have to say I didn't get a hell of a lot out of it. I was surprised given its age, but then I flush and skim it at least once a year, and I've used Scale Flush (formerly Steamaster) for the last ten years or so.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
    Long Beach Ed