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Loud Water Hammer Everywhere

cornealcorneal Member Posts: 4
Hi All,

I am new to this forum. I purchased a house a little over a year ago built in 1920 with a single pipe system boiler and steam radiators. I have a Utica Boiler.

Work I have done: Replaced two main vents with Gorton #1 valves. Replaced all air vents on radiators with Hoffman #40. Replaced two bedroom radiators with 1.25" steam radiator valves. Pitched and shimmed all radiators to steam valve. Checked/verified slope of all piping in basement to boiler return. Eye glass is water is clear.

The issue: We are getting VERY loud water hammer in one of our bedroom radiators as well as several others. The upstairs radiators sound like they have water bubbling in them. I have no clue what is happening and seeking professional advise. I have been using a local plumbing contractor who seems familiar with steam but this issue has not been solved. Two thoughts I have....The supply pipes to the upstairs radiators are in the exterior walls with no insulation, could the water be condensing quickly and causing the water hammer? The other concern I have is the contractor said my nbp is incorrect, could the piping having anything to do with throwing water into the system at start up?

Please help! I have a baby on the way and the nursery is the loud radiator! also our guests can barely sleep in the guest room. Photo attached of nbp.

-Chris (Annapolis MD)


  • ethicalpaulethicalpaul Member Posts: 1,623
    It's hard to tell from the picture because I can see it's tight in there, but yes, your near boiler piping looks to me like it could be throwing tons of water into the rest of your system.

    There is a great steam contractor in Baltimore who is on this forum, you should have him check your system out. Look for him in

    Do you cover Annapolis, @Gordo ?
    1 pipe Utica 112 in Cedar Grove, NJ, coal > oil > NG
  • JUGHNEJUGHNE Member Posts: 6,971
    Go to "Find a contractor" on the main site above.
    Call "All Steamed Up"...... would be my recommendation.

    In the meantime what pressure shows on the gauge when steaming? Has the pigtail been cleaned?
  • Hap_HazzardHap_Hazzard Member Posts: 2,263
    The bad news is that the near boiler piping is totally wrong. The header, if you can even call it that, is no bigger than the risers, which are much too short, and the system riser comes off between the boiler risers, leaving no way for water to return to the boiler, and I don't even see an equalizer. Maybe it's just not visible in the picture, but it's hard to see where it would be connected if there is one.

    The near boiler piping on Utica boilers is critical because the supply tappings exit from the sides of the boiler, barely above the water line. The way this has been piped seems almost designed to force as much water into the system as possible and keep it there, so of course there will be steam hammer, but it's also causing massive fluctuations in the water line, which can shorten the life of the boiler. The hammering you're hearing is a cry for help.

    The good news is that you live in Maryland, not far from @Steamhead and @Gordo, of All Steamed Up, Inc. They are two of the best, most respected steam men in the business. If you search for some of their posts in this forum you'll find many examples of their work, which speaks for itself.
    Just another DIYer | King of Prussia, PA

    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • FredFred Member Posts: 8,423
    I agree with all the comments above about the near boiler piping and the recommendations for Steamhead and Gordo.
    Having said that, try to raise one of the second floor radiators up (on both ends) about a half inch (if possible) and then re-pitch the radiator. It is possible there is a short length of horizontal piping under the floor that has lost it's pitch and is holding water. Raising the radiator a bit will help restore the correct pitch.
  • BobCBobC Member Posts: 5,112
    Old houses settle and that can throw piping out of pitch. I agree with @Fred that upstairs radiators could be culprits. Use a 2X4 and fulcrum to GENTLY lift the radiators and shim both sets of legs with shims. I've used strips of plywood (1-1/4 wide) under each set of legs. In my case 3/4" at the far end and 1/2 under the shutoff valve end did the trick.

    Make an appt with @Steamhead or @Gordo to have the system looked at, that near boiler piping is just bad.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • ethicalpaulethicalpaul Member Posts: 1,623
    Yeah if it were me I wouldn't even mess with the radiators until that piping was sorted.
    1 pipe Utica 112 in Cedar Grove, NJ, coal > oil > NG
  • cornealcorneal Member Posts: 4
    Thanks everyone for your comments. I have received one quote to reconfigure the near boiler piping. Says the following...

    "Correct near boiler piping. Includes eliminating copper and installing steel, pipe return into new Harford Loop, and install equalizer piping down to Harford Loop"

    I have also messaged @Steamhead to see if they can come out of a look as well.
  • Hap_HazzardHap_Hazzard Member Posts: 2,263
    I hope the plan isn't just replacing the copper with steel. You really need a proper header, with swing arms, preferably a drop header and taller risers.
    Just another DIYer | King of Prussia, PA

    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • cornealcorneal Member Posts: 4
    Okay, thank you. I am hopeful that I can get one of those experts out so I can get the best professional opinion.
  • SeanBeansSeanBeans Member Posts: 483
    I would get @Steamhead out. Can’t help but laugh out loud when I see piping like that
  • JUGHNEJUGHNE Member Posts: 6,971
    If you go on line to the Utica website and enter your model number, you can download the Installation & Operation book, (I&O manual). The entire book might be 50 pages long.....good to keep at the boiler for future reference. What you really want to see is piping diagrams.
    These boilers are troublesome for throwing water up with steam and need to be piped by the book at a minimum.
    The side outlets both must be used and be full size of the boiler tapping. Usually 2 1/2".
    Yours looks to be reduced just under the jacket to 2" copper.
    The extra cost of "drop headers" would be well worth a minor upgrade cost.

    Keep us tuned in.
  • cornealcorneal Member Posts: 4
    edited January 7
    Here is a diagram I found from the manual.... Also my information plate on the boiler. Looks like I have a model size262, which should be 3" pipes.

  • dopey27177dopey27177 Member Posts: 306
    See attachment.

    The attachment will show the proper Dimension A for boilers over 100,000 BTU out put as well as the main vent valve placement.


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