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One Pipe Steam Heat, Water Hammer

I purchased a house two years ago and this will be the second winter in the house. The house was a flip and the previous owners had both the water heater and steam heater replaced with brand new equipment (both natural gas). The steam pipes all remained the same except for one line which was replaced with copper piping and was also split into two radiators on the second floor. One is a baseboard radiator the other is a standard radiator. This line produces severe water hammer and occurs mainly when the system has just turned on. Both radiators also spit water out of them.

I had a plumber here at the end of last spring because some of the air vents on the first floor were spitting water, as well as one of the valves leaking. The plumber replaced all of the air vents on all radiators (9 total). He also re-packed all of the valve nuts. I asked about the water hammer and he told me that the air vents should take care of it. He also pointed out that the new line they ran to the second floor is not pitched correctly. The horizontal pipe is pitched away from boiler; he suggested that the vertical pipe may need to be shortened to allow for proper tilt. I asked for a price to have this work done but he never got back to me. He also cleaned the boiler with cleaner.

Some other observations that I see are that there are no main air vents on the system. There is no insulation on any of steam lines. On the two "new" lines there is no shutoff valve for the baseboard radiator. I can hear what sounds like metal rattling around shutoff valve. (I find this weird because it is a brand new shutoff valve) I can hear the steam coming out of all of the air vents. Finally the radiator closest to the boiler also spits water every once in a while. I also hear rattling in the shutoff valve. Today when I looked at the water in the water tube, it was rusty colored. When I put my ear up to the wall is sounds like water is rushing up/down the pipes (all water lines are off when I listen)

I was planning on calling in another plumber to take a look at the system. Can you give me any advice on what I should have them look at? Or what should actually be done. Plumbers aren’t cheap and I want to be as educated as possible when the next one shows up.

If you need pictures please let me know what you would like pictures of.

Thanks in advance for your help,


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    edited December 2014
    You need a steam professional, instead of a mere plummmmer. They both work with piping, but their spheres of knowlege can be quite different.
    I would think you have over-pressure due to a clogged pressuretrol, and maybe badly installed boiler piping, which is causing huge amounts of water to be thrown up into the piping, instead of just dry steam.
    The new copper piping may not be pitched right, and should not be done in copper, due to its high expansion, and contraction properties, which will soon break the joints.
    What is your location, for some names of competent pros?
    There are some excellent books in the shop here which after a few evenings of pleasant reading, will give you more knowlege of steam systems in general, than most of the plummmmers out there.
    Many people have gathered the knowledge to repair various problems with their systems, and so may you if there are no knowledgeable pros around your area. Pictures of your boiler, and rads would be very helpful.--NBC
  • scruffmagruff1214
    Thanks for the quick response. I am in Worcester county Massachusetts. If you could recommend a steam professional that would be great. I got this website from a book I just picked up, we got steam heat. Very informative for a new homeowner.
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,322
    Some plummmers know steam NBC. Call me I go to Worcester fairly often. Pictures always help.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Jamie Hall
    Jamie Hall Member Posts: 23,295
    I third that -- call Charles. Busy man, but he'll get you straight
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • scruffmagruff1214
    Here are some pictures of the boiler, and the radiators that leak. the last two radiators shown are the ones that leak the most. they are also connected together in one line. they are in two rooms next to each other, on the second floor.("new" line as described in the original post)
  • scruffmagruff1214
    image 5640 is closest radiator to the boiler, spits water out of the vent occasionally. image 5637 is the first floor bathroom, second closest radiator, and underneath radiators that leak bad. both the first floor bathroom and the second floor bathroom had new pipes run with copper lines.
  • Abracadabra
    Abracadabra Member Posts: 1,948
    looks like you've had some work done since the dead men installed the piping. I'd replace the varivent and use something like a gorton #4 or #5. Your near boiler piping leaves much to be desired and I believe is contributing to wet steam. The radiator in #5648 might need a bigger pipe going vertical. We'd have to know it's EDR. You need to make 100% sure that horizontal is pitched very well.
  • ChrisJ
    ChrisJ Member Posts: 15,683
    Please call Charlie.
    He'll make it right.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Fred
    Fred Member Posts: 8,542
    edited December 2014
    Call Charlie. That stair step Riser, with what looks like a drip leg on it going to what looks like 3 Mains is just not right. (If I'm seeing it correctly). The stair step isn't the problem but that drip leg and the 3 mains fed off of the one riser certainly are. IT IS QUIT POSSIBLE I'M NOT SEEING IT CORRECTLY. THE PICTURES SEEM TO HIDE/EXPOSE PIPES AT DIFFERENT ANGLES???