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Losing 10 gallons/month

impossibleimpossible Member Posts: 11
edited February 22 in Strictly Steam
I have a Weil McLain peg-40 boiler one pipe system which has been loosing about 10 gallons a month going back to last season. My research tells me the culprit may be a buried wet return line. Since fresh water minerals are bad for a boiler, do I have time to wait 3 more months until the season is over before I dig up and replace the pipe? Going back to last season, I’ve gone through about 100 gallons. I really don’t want to tackle this during the winter season since Ive never done this before but I've done my fair of research and am confident I can do the job. I just prefer not do it during cold winter season.

My tentative plan is to replace the current steel pipe with copper and add a couple flush valves on each end. Not sure how I make the transition but I'd look to use 1.5” brass unions so corrosion doesn’t occur.


  • mattmia2mattmia2 Member Posts: 1,729
    Did you flood the boiler to make sure there isn't a leak above the water line and it isn't going up the flue?
  • JohnNYJohnNY Member Posts: 2,477
    If it loses water when you're not using it then it's your return.
    For troubleshooting and private consulting services, find John "JohnNY" Cataneo here at :
    "72°F Mechanical, LLC"
    Or email John at [email protected]
    John is the Boilers and Hydronic Heating Systems Course Instructor at NYC's Mechanics Institute, a professional Master Plumber, licensed by The Department of Buildings of The City of New York, and works extensively in NYC while consulting for clients in and out of state.
    John also oversees mechanical installations and maintenance for metro-area clients with his family's company, Gateway Plumbing and Heating along with his brother/business partner.
  • SuperTechSuperTech Member Posts: 1,390
    Losing, not loosing
  • Jamie HallJamie Hall Member Posts: 13,202
    A few more months at that rate of loss -- since it's been going on for a while -- won't likely do that much more damage. But the sooner the better...
    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
  • ethicalpaulethicalpaul Member Posts: 1,713
    edited February 21
    It's interesting. It looks like they repiped the above-ground part of your wet return at the same time they installed the boiler. And if they did that, it must have been because those pipes were rotting out. So I wonder why they didn't think to test or just replace the underground part. (I mean, the obvious answer is $)

    Here's the crazy thing I would do. Go ahead and chisel out the mortar patch and purchase and size/cut your copper now during the cold season. On a warm weekend repipe the copper below the floor. Instead of mortar, cover it with pressure treated wood or composite deck material. Make the cover be upside down U shaped so it doesn't put force on the pipe. Plumb it with isolation valve(s) and garden hose bibs for easy flushing (I see one is already there). You don't have to bury the pipe in dirt, you can let it sit above the dirt and below the deck bridge you made for it.

    It's so nice having the return below grade I think all this is worth it. You'd also be able to see if that really was where your leak was and then post pictures of the rotten pipe for fun. The best thing about working on your own system is you get to do fun things like this.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 7,223

    Dig it up (it's been dug up before so the diggings easy) But I wouldn't dig it until I had the new material on hand...just in case. Just digging may finish the old pipe off.

    Get your new material and do it as soon as the weather is warm. Dig the trench out big enough so you can put armaflex pipe insulation on it. This will keep the pipe away from the concrete and the dirt
  • Hap_HazzardHap_Hazzard Member Posts: 2,263

    Dig the trench out big enough so you can put armaflex pipe insulation on it. This will keep the pipe away from the concrete and the dirt

    That's a great tip. I'd even recommend insulating wet returns that aren't buried. When my wet return rotted out I noticed that most of the corrosion had happened on the outside of the pipe. Basements tend to be damp, and water condenses on the return piping when it's cold, and since there's plenty of oxygen available, it rusts. Insulation will make the pipe last a lot longer.
    Just another DIYer | King of Prussia, PA

    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • EBEBRATT-EdEBEBRATT-Ed Member Posts: 7,223
    Must cofess it's not my tip.I found it on here I think it was @DanHolohan
  • FredFred Member Posts: 8,432
    From the looks of those Mains, it looks like a counter flow system. I think I even see a drip on one of the mains. What do those wet returns go to? Do the mains change pitch and become a parallel flow somewhere along their path?
  • nicholas bonham-carternicholas bonham-carter Member Posts: 8,169
    It’s time to do the overfilling test, recommended above, because that amount of water loss is unnatural.
    Fill it up, when only warm to the header, where you can feel the cold water, and let it rest, for an hour or so. Any boiler leaks will be seen in the firebox, or on the floor.
    Don’t forget to drain the excess water out when turning it back on.
    Do a survey of your radiators to find their EDR, so you can size the replacement, if it appears you have a boiler leak.—NBC
  • dopey27177dopey27177 Member Posts: 378
    Rather than bury the pipe again why not run it along the walls above ground. You can support the pipe with J hooks from the wall.

    There may be a short run of pipe that may need to be buried you can bury the copper tubing below grade but cover it with clea sand. Where the copper pipe comes above ground use pipe sleeves to protect the tubing from the concrete,

  • impossibleimpossible Member Posts: 11
    Thank you all for all your suggestions and help. I am not sure I would be able to do this the right way without this forum.

    I finally got around to digging up my basement floor. Not to my surprise, I found a 3/4 inch hole on the underside of the buried pipe. I could now use some suggestions on which materials I need in order to repair the problem. I did extensive googling and learned that I should replace the iron pipe with copper, add a flush valve on each end and use 1.5” brass unions so corrosion doesn’t occur between the two metals.

    There have been some great recommendations here but since this is a well traveled area in our basement, I've decided to bury the line again.

    I am hoping you can answer the following questions…

    1) What size copper pipe should I use? Match the current 1.5”?
    2) I don’t know what a flush valve is. I googled it but all I come up with are toilet valves.
    3) Should I use brass unions to connect the brass to the current piping?
    4) Where would you cut the line? ABC? 123?

    Thanks again for any tips you may have. I will continue to post pictures of this project for future reference.


  • Jamie HallJamie Hall Member Posts: 13,202
    1.5 inch is fine. For your backfill, though, use clean sand -- no concrete. The pipe will last longer. You can place concrete over the top a few inches up for the floor, but make sure the sand is well compacted before you do.

    By flush valves in this application (yeah, Google would come up with toilets...) I'd recommend full port ball valves, but with an arrangement at one end so that you can also hook up a hose and blast away.
    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
  • dopey27177dopey27177 Member Posts: 378
    replace size in kind.

    Be sure you have valves installed to isolate the line and hose valves to be able to flush out the wet return when needed,


  • JUGHNEJUGHNE Member Posts: 7,098
    Isolation valves on each end. Then a Tee just below each valve that has a valve and hose fitting.
    IIWM, the one at boiler would be such that you can flush all wet return lines, including the exposed above floor lines, from the other end without pushing all the junk into the boiler.

    You can flush from either direction if needed.
    I use washing machine hoses for my double female connections.
  • impossibleimpossible Member Posts: 11
    Removed most of the sections, pics below...

  • impossibleimpossible Member Posts: 11
    edited September 17
    I was able to remove most of the old work but cannot get the last portion off. It is my understanding that I can't simply cut the iron pipe and fit a new piece onto the cut end? I must unscrew leaving threads so I can screw a new piece back on? Well probably not a shocker but I'm having a hard time getting the old threads to break, at least with two 14" wrenches and a 2 foot "breaker" bar. I'm looking for any suggestions on how to unscrew the old pipe. Should I try heating with a torch? I'll keep hitting it with PB blaster in the meantime

  • mattmia2mattmia2 Member Posts: 1,729
    edited September 17
    Try unscrewing any of those 3 and replace from there. If you can unscrew that ell from the horizontal pipe you can cut the close nipple between the 2 fittings to unscrew it. Might just need longer pipes on the handle of the wrenches. Make sure the back of the wrench is seated on the pipe so it is less likely that you crush it. Heat could help too.

    Could also cut the outside of that ell at the horizontal pipe with a hacksaw or grinder to just before you get to the threads and split ti with a cold chisel. Those fittings may also be the right kind of iron to shatter of you back it up with one short handle sledge and hit the opposite side with another one.
  • impossibleimpossible Member Posts: 11
    Thank you mattmia2! The sawzall/chisel method worked great!
    Going to take these old pieces to the plumbing supply center tomorrow so I can get my new parts....

  • ethicalpaulethicalpaul Member Posts: 1,713
    Nice job! I used like a 5 foot "helper" pipe to break my 2" steam pipes. They really hold on.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG
  • impossibleimpossible Member Posts: 11
    How'd I do?

    Lucky I started this project, woke up this am here in NJ and it was 52 degrees. After I confirm my work is water tight, I will patch the floor and fire the boiler up. Is that all there is to it?

    Thanks again for all the tips. The guys at the plumbing supply house loved the idea of wrapping the underground copper with Insulation.
  • Danny ScullyDanny Scully Member Posts: 1,253
    edited September 19
    Looking good, although I would insulate the piping completely as it comes up though the floor (mitering the elbows). 
  • mattmia2mattmia2 Member Posts: 1,729
    Bring the insulation out of the floor at the end and cut it so it butts together around the ell underground. The idea is to provide a barrier between the corrosive soils or concrete and the copper. Leave it sticking above the floor a couple inches.
    Danny ScullyCanuckerimpossibleethicalpaul
  • impossibleimpossible Member Posts: 11
    Thanks all. Back in business here.
    Hope this thread helps someone in the future.

  • JUGHNEJUGHNE Member Posts: 7,098
    I don't see an isolation valve on the end where you cut the old iron 90.
    If you connect house pressure to either hose bib then water/sludge could/will back up into your steam main/returns if your under floor pipe was slightly restricted.

    If you do not have a valve on that side somewhere, I would cut one into the copper riser and then a hose bib below it for flushing.
  • dopey27177dopey27177 Member Posts: 378
    I for one would not use gravel or stones as the fill before re-cementing the floor.
    fill the hole with sand (pre washed no salt in sand) then re-cement the floor. The cement is cheap enough. You can buy redi-mix at home depot or lowes centers. You do not need to add the gravel for a stronger Concrete mix as the basement floor is not a load bearing floor.

    By the way the job you are doing is about as professional as it can get.

    Nice work

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