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Old boiler re-piping?


I have a 1979 Dunkirk natural gas steam boiler that was originally installed incorrectly. There is no header and the tappings have been reduced in size with bushings. The Hartford loop is very close to the steam production. When the steam comes out it hits a bullhead tee.

The boiler has been working this way for a very long time but has these problems: very bouncy water line, water being forced out of the boiler into the mains (wet steam) and water hammer in the Hartford loop. Because of these problems the system has to be run with a lot of extra water.

I would like to reconfigure it with a 3" header, 2" equalizer and two risers one for each distribution main. The Hartford loop will be on the other side of the boiler. I plan to do this work myself after the heating season ends. I've been doing all of my own plumbing with some help from plumbers in my family. Last summer I replaced the wet return which was leaking badly.

My question for the forum is it possible to do all this work including removing the bushings from the boiler tappings without breaking the boiler? If I do break it I'm prepared to buy a new boiler but wanted to try this approach first. Do I have a chance at success or is this just a terrible idea? Any tricks for taking the bushings out? I imagine it will be similar to taking the spud out of a radiator which I have done previously.



  • redoing the piping oneself

    yes, but of course wait until summer!

    the use of a drop header will make it easier to get the header laid out properly, and will make the steam dryer.

    there is some sort of procedure described here for the removal of old bushings with melted paraffin wax. do a search and maybe the details of that will pop up. of course that may be more effective while the boiler is still running.--nbc
  • Brad White
    Brad White Member Posts: 2,393
    Might there be

    Another riser tap in that boiler of yours? So many times I have seen, "one and done" and it never occurred to me until I started coming here what the other one was for.

    You have the makings of a superior system and the foresight to know it. Time to start will be here sooner than you think, so plan and have fun!
    "If you do not know the answer, say, "I do not know the answer", and you will be correct!"

    -Ernie White, my Dad
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,216
    You may find this summer

    when you go to remove that bushing the inner workings of the boiler are so plugged you do not want to continue your course of action. I strongly feel you should opted for a properly sized new boiler. Your every day car I am guessing is not a 1979. The idea is what is practical not what is possible.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Brad White
    Brad White Member Posts: 2,393
    Good Perspective Charlie

    Especially the 1979 car analogy. Well said.
    "If you do not know the answer, say, "I do not know the answer", and you will be correct!"

    -Ernie White, my Dad
  • davidsorkin
    davidsorkin Member Posts: 16
    replace pros and cons

    Brad: Yes the boiler does have a second tapping but it has a plug in it that I am not sure yet how to remove. It does not have a head but has a square recess that looks a very large socket wrench driver about 2" x 2" would fit into. From the owners manual only one riser tap is required so I wasn't planning to use both. Is it advisable anyway?

    To Charlie's point my goal is to see if I can make some improvements this year without too much expense. I imagine a new boiler will cost many times more than pipes and fittings I would need. If the thing falls apart when I am working on it or looks like it's on its last legs then then at least it will be in the summer and I can replace it. If instead I can cheaply fix it up and make it work better for a few more years then what is the advantage of replacing it now? How long could it hypothetically last? I was thinking of it as more like a cast iron frying pan than a car. I also drive my cars until they're dead ;)


  • Charlie from wmass
    Charlie from wmass Member Posts: 4,216
    David Frying pans are treated nicer

    than your boiler is. If a boiler is over 5 years old I would not spend a customers money on repiping it. I used to drive cars until they died. I can not afford to do that any more. The day the new boiler properly piped goes in you start saving fuel. The new piping may not line up with the next boiler and could require a major labor cost to match things up. Lots of coulds and maybes. Do you have a photo of your current boiler? As far as trying to remove a 30 plus year old recessed plug. I would say let sleeping dogs lie. The bouncing water line may already have caused corrosion at the water line that is already or close to leaking. Also what is the rating of this boiler? Many old manuals, especially from the 1970's used 2" and single risers for boilers that needed much larger to work well.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Costs

    The pipes and fittings for a quality installation of a new boiler typically come out to almost the cost of the boiler, especially when  as much repiping is needed as you need.  And, what is your labor worth?  Start all new and be done with it.
    The Steam Whisperer (Formerly Boilerpro)

    Chicago's Steam Heating Expert

    Noisy Radiators are a Cry for Help
  • crash2009
    crash2009 Member Posts: 1,484
    The devil in me

     likes the idea of torturing it for awhile.  Might be easier to do that in the back yard though.
  • davidsorkin
    davidsorkin Member Posts: 16
    Summers not here yet

    Points well taken. I should say any work I do on this this thing is a "labor of love" and more of a hobby than anything else. It's a rare and enjoyable opportunity enjoy when I get to do something with my hands since my day job is corporate IT.

    Boilerpro: Does the cost you are referring for piping assume labor or just materials? My goal was to get all the 2" and large pipe cut and thread for me at the local plumbing supply house. Anything else I can make myself with my hand threader.

    Based on most of the feedback I'll start investigating new boilers but I still plan to take this one apart. Once it's all dissembled I'll take a bunch of new pictures and maybe the folks here would be good enough to reassess at that time.

    I still have one question remaining. If we make some generous assumptions and I successfully re-pipe it could I potentially get another 5 years service out of the boiler?


    These photos are from before I replace the wet return and put in a new LWCO and automatic water feeder.
  • jimmythegreek
    jimmythegreek Member Posts: 56
    edited February 2011
    life span ?

    you could keep that sears job running forever if it doesnt leak and replace parts/controls.  It depends on what you wanna put into it time wise and $$ wise.  If youy were doing all the work yourself you wont have that much in parts really.  In the pic of the stripped section it looks to have another side tap on the other side of your steam tapping.  Utilize it on repipe and make a proper equilizer and loop.  If your doing it all in 2" you'll have a couple hundred in fittings and pipe, and I would replace that honeywell control or at least rewire it, it looks sketchy my friend.  Also extend that pressure releif valve down to the floor and if it leaks replace it and put some guages on that sucker please.  There is NEVER a good reason for not having a working pressurtrol or some sort of cutoff device on any boiler, steam or otherwise.  No pigtail in pics and just a factory guage tucked into the jacket straight into the boiler, that guage is toast for sure.  The releif valve is prob rated for 15psi, if its dripping from pressure, you got a whole lotta problems over there, you should be at under 2 psi tops............
  • davidsorkin
    davidsorkin Member Posts: 16
    Re-piping complete!

    Thanks everyone for the feedback and the encouragement. I

    successfully finished the reinstall yesterday!

    I ultimately decided to reuse my old boiler for a few

    reasons. The main reason is that I was able to do the job at 25% of the cost

    and if I had to buy a new boiler the wife would have vetoed the project. Another

    reason is that this boiler has been frustrating me for almost 10 years because

    of the poor job done when the boiler was initially installed. I knew that it

    was a good, working boiler and properly sized for my house. It was a matter of

    personal satisfaction for me to finally get to see it working like it is

    supposed to. The last reason is that I just like the idea of re-using /

    reconditioning old parts rather than just throwing out and always buying new. I

    think most people here would agree with me that that is a more sustainable

    model. I feel very confident that the boiler will now last at least as long as

    I think we will be living in the house until my kids are bigger and we need

    more space (~5-7 years).

    It turned out to be a humungous job. Getting the countersunk

    plug out was probably the biggest challenge. I initially tried a cleanout plug

    wrench, soaking it with penetrating fluid, a torch, attempting to bang it

    loose, etc… I even tried using a 4' pipe wrench, 5' cheater and a hydraulic

    jack at the end and only succeeded in twisting the plug wrench 45°. At that

    point I gave up and tried a new approach. I drilled a big hole in the middle of

    the plug with a step bit, used a Sawzall to cut radialy out most of the way but

    stopping before it cut into the threads and then chopped the arcs out with a

    hammer and cold chisel. This method worked very well but it wore out a lot of


    The next major challenge was taking apart the distribution

    piping to the point where I could connect new pipe. Again lubricating oils,

    torches were of no help. Using the big wrenches only succeeded in crushing the

    pipe. Finally I got some help from my 90 year old grandfather who had his own

    plumbing business for many years. He showed me the two hammers method to break or

    loosen a cast iron fitting. It involves two 4 pound hammers, one is held

    against the fitting and then repeatedly strike from the other side with the

    other hammer. After quite a bit of banging on a cast iron elbow that had

    probably been there since 1935 it did not break but it loosened and was able to

    be removed. The pipe threads underneath where in very good shape. I also had to

    remove half of a union which is not made of cast iron so the two hammers trick

    does not work. For that I got a tip from the local plumbing supply store. I

    used an angle grinder with a metal cutting blade to cut a grove across the

    fitting, again being careful not to cut too deep and damage the threads. After

    a few groves were cut I used a big screwdriver to lever out sections and it

    came right off.

    With the boiler fully disassembled I decided to do a

    pressure test. I plugged all holes and filled it with water and saw that it maintained

    20 psi.

    Reinstallation of the boiler was fairly straightforward. It

    was again more work than I initially hoped because I realized it would work out

    a lot better if I rotated the boiler 90°. This in turn necessitated moving the

    gas line and water feed piping. Dan's Lost Art of Steam Heating was a great

    resource in coming up with the design. I looked at all the drop header photos

    on this site. In the end I made two 2.5" risers (same size as boiler

    tapping), a 3" drop header and a 2" equalizer and kept it 2" all

    the way back to the boiler. Maybe this was overkill but it seemed to be

    consistent with all the advice from the forum and Lost Art. I put in a dirt leg

    at the bottom of the equalizer with a drain that also serves as the drain for

    the boiler. This way the dirt leg gets cleaned out as a matter of course. On the

    other side I piped the riser with a tee fitting and valve so I can easily do a skim cleaning. I

    piped the pressure safety relief valve with a tee fitting, elbow and plug so I

    can add chemicals without taking the whole thing apart. There is a valve in the

    return line so I can give the wet return  a "steam cleaning" when necessary. I

    put in king valves so I can increase the boiler pressure to blow out gunk from

    the bottom. I put a valve underneath the pigtail that goes to the pressure

    control and low pressure gauge so it can be disabled for such a high pressure

    cleaning. I also replaced the original 0-30psi gauge with a factory replacement because

    it was broken. I used all brass fittings and nipples for glass gauge and low

    water cut off assembly. Brass just looked nicer. The boiler tappings for those

    utilities are only ½" but the LWCO probe is ¾" so I used an eccentric

    fitting to make sure the water could drain out. Finally I put all the

    wiring inside of BX instead of just duct taped to the gas pipe like it used to


    Everything took a long time because I had to order a lot of

    the fittings online. I went with imported malleable iron fittings because it

    saved me hundreds of dollars. Any time I tried to by something locally I found

    it cost about twice as much even with trade pricing. The home supply center near

    me cuts and threads pipe up to 2" for free so they made most of my custom

    pieces. I was able to order some larger diameter nipples online. I had to get

    one piece of 2 ½" pipe cut and thread at the local plumbing supply store

    for a small fortune.

    So after 5 months of working on it all summer and just in

    time for the cold weather I was ready to test it last night. Completely gone

    were the problems it used to have. The water stayed in the boiler and did not

    percolate out into the piping any more. The water line was stable for the first

    time ever. The low pressure gauge needle did not jump all over. The system

    heated up quickly and for the first time produced dry steam. This morning I

    timed it and it took 37 minutes before cutting off at 1.5 PSI. Before when it

    was coming on the air vents would hiss in spurts, loud hiss, nothing, loud

    hiss. I think that air was actually getting sucked back in between hisses. Now the

    air vents are smooth, constant and quiet until they close when the steam hits.

    For my next step I just need to give it a cleaning and put

    the fiberglass insulation on the new pipes.

    I know a lot of people think this type of work should not be

    done by non-pros but I really enjoyed doing it and I think I did a job that may

    even exceed the quality that a professional might have done. Certainly I did a

    better job than the "professional" who installed it in the first

    place. It is my humble opinion that none of this stuff is magic and that anyone

    with an inclination, enough patience, willingness to learn, assess risk, do

    research and correct mistakes can work on a steam system and install a boiler

    even if they are a homeowner. After all, it is my house!

    I wish to extend thanks to Dan Holohan for his books and

    articles along with this forum and its contributors whom have been a great help

    and inspiration.

    Photos will be posted soon.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    As one non-pro to another ...

    Sounds as though you did a great job.

    You might get a gas pro in there, though, to set up the gas burner and adjust it with combustion analyzer.
  • davidsorkin
    davidsorkin Member Posts: 16

    Here are some photos. Next step is insulation.
  • Steamhead
    Steamhead Member Posts: 15,504
    I agree

    that's a re-branded Dunkirk Plymouth, which is known to not tolerate improper piping. But a good steam pro would be able to build a good header for it, and do it in such a way as to not need much modification when the boiler is replaced.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • moneypitfeeder
    moneypitfeeder Member Posts: 248
    edited October 2011

    What a great job! I am impressed by your install ( I'm also with getting a pro in to check your flue gases) I just repiped mine, but did not tear down to the level you did. I only messed with the piping out of the boiler; the gas line, and vent lines I didn't touch. It must feel really good to know you have been able to affect your own home's comfort in such a way, I know I love it. Good Job! Dee
    steam newbie
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,778
    Nice work.

    I think I might be doing the same to my old Peerless boiler. I repiped the return this summer, and I also installed a CycleGard and a VXT and gave it a thorough cleaning.

    I also had to get a little creative to be able to skim mine. The IOM that came with my boiler didn't show a skim tapping, and there isn't one where the newer manual says it should be, but I found an unused tapping under the safety valve at the water line--it's only 3/4", but it's better than nothing. I also put ball valves on everything to make the routine cleaning easier. My trick for getting those old boiler plugs out is to run an air hose in from the garage and use my 1/2" impact wrench. Penetrating oil doesn't buy you anything because of the pipe joint compound they put in there, and the heat can't work in your favor either, so impact is your friend.

    Did you know they make a 1/2" probe for the CycleGard? Most places sell them with the standard probe, so you have to pay extra for the smaller one, but you could probably sell the standard one here.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • davidsorkin
    davidsorkin Member Posts: 16
    skim tapping

    I was able to contact Dunkirk and they sent me a scan of the original manual for my boiler. It showed the skim tap set up this way. Of course the tappings have to be on the side of the boiler.

    Unfortunately I did not know about the 1/2" LWCO probe. It would have saved me a lot of trouble!
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,778
    I asked Peerless

    I tried to get that information out of Peerless and they were pretty far from helpful. I asked if they could tell me how old the boiler was, since the serial number didn't fit the pattern they described in their FAQ, and I asked where the skim tapping was, since the IOM for the 561 didn't show one and there wasn't a tapping where the 61-05 IOM said it should be. They just said, "It is on the left side 1-1/2" tap and should be done by a qualified service person."

    I have two problems with their response. There is no 1 1/2" tapping on the left side of this boiler, so they don't know their own products, and they don't say what they mean by "qualified." I know how to skim a boiler. If they're jumping to some conclusions about my qualifications, they could at least do me the courtesy of telling me what they are. Otherwise they're just being denigrating and dismissive.

    Still, I'm glad I asked. Before this happened, if I'd decided I needed a new boiler, I probably would have gotten a new Peerless. Now I think I'll shop around. They didn't impress me.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
This discussion has been closed.