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water hammer help! video included

Hello – I am a new homeowner with a steam system in an old house. This is my first winter in the house and the loud noises from the steam radiators make it very difficult to sleep. There seems to be only two bedrooms in the house that have loud radiators and they are both next to each other and are the last two radiators in the whole system to actually heat up and have any sort of steam noise coming from them. Both radiators are tilted towards the single pipe heading towards the floor (verified with a level). The valves on the floor are turned completely in the on position (at least from what I can tell). From what I can see, the water in the furnace is clear and I have tried lowering and raising the water level to try a different level. The PSI seems low (~2) on the furnace. All noises seem to be coming from the radiators and not from the pipes in the walls/floors.

Here is a link to a video which demonstrates the noise (usually lasts a few minutes):

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I have tried searching through the forums and guides here but a lot of it seems complicated for someone not setting up a new system.

Anything to do to reduce this noise? Is this noise considered normal? Any tips are greatly appreciated!



  • Two loud ones

    Can you draw a diagram of where these radiators are in the system. For instance, are they they fed first off the main, or last?

    I suspect that there is a sag in the intervening pipes which is trapping water, and mot only slowing down the water, but also causining water hammer.

    If you can takeaway level, and make sure the steam mains are all sloped in the same direction, this would show wheretheproblem is. Once you have found the problem are, we can advise a solution.

    Also check the pressure settings of the system, and make them as low as possible.--NBC
  • JStarJStar Posts: 2,668Member

    You can also try to blow through any trapped water. When the system is off, remove the vent and blow through the opening. Replace the vent, and run the system. This "fix" will only work once, though, as the water will eventually fill up again.
  • steamheatnewbsteamheatnewb Posts: 14Member
    thank you

    Thank you for the follow-up! These two rooms are the last two to heat up so I believe they are not off the main. Because they are not on the ground floor, its difficult for me to see what is going on before the steam gets to them. The noises sound like they all happy mid/early cycle. Since I am new to this, can you send me a picture of what the pressure adjustment might look like on my furnace? There is one gray box that has a lever that could move up and down, could this be it?

    Thanks again!
  • JStarJStar Posts: 2,668Member

    Here's the Pressuretrol. It should have a Cut In dial on the front and a white wheel on the inside
  • steamheatnewbsteamheatnewb Posts: 14Member

    Thank you Joe! I can try this. Is this the vent you are talking about:
  • Loud and close

    There are some books in the shop here which would fill in any gaps in your knowledge of steam here. I would suggest getting all 3.

    Is there a pro in your area who could get a start on this system?

    He should show you how to check the pressure of your system, clean the burner, check the radiators for proper pitch/drainage, and check the operation of the air vents.

    When first installed, your system would have been virtually silent, and more economical than forced air. Some thing has changed over the years, and now it is loud, and probably inefficient.

    The mark of an expert steam pro would be in his familiarity with this website!

    If there is no one local, then we will have to lead you through the system step by step.

    Post some pictures of the boiler here, and we can look for any obvious deficiencies.--NBC
  • steamheatnewbsteamheatnewb Posts: 14Member
    edited January 2013
    quick follow-up

    I took a few pictures of the furnace after it has been running for a while in the AM. Attached is the setting on the steam pressure (very low), the color of the water, the PSI in the system and some other adjustment that I am not sure what it is that is located near the hot water heater. Any red flags here based on the images?

    I picked up "The Lost Art of Steam Heating" but I felt it was over my head!

    As always, thanks again!!
  • steamheatnewbsteamheatnewb Posts: 14Member
    SUCCESS! almost...

    So far the water hammer noises have stopped! One of the radiators in the living room was partially closed. I turned this radiator on and now there are no more water hammer noises.

    Unfortunately this introduced a new problem... the radiator in the living room must have been closed because it leaks. There is a small drip (about 2oz per cycle) that is happening at the bottom / center of the radiator. So far I have a pain tray under there to catch it but need to find a better solution long term. Any recommendations? Has anyone tried FlexSeal on the outside of the radiator? Looks like its good for 500+ degrees. The website says no radiators because of the pressure but steam radiators are very low pressure so I assume they are talking about car radiators.
  • ChrisJChrisJ Posts: 9,817Member

    Honestly I have never repaired a radiator and may never get to as 9 of my 10 do not have the threaded rods that pull them together.  They instead use special threaded couplers I forget the exact name.

    However it looks like yours may have the rods that hold it together and I beleive those push nipples are still avaliable.  Hopefully someone who knows more about it can respond.

    By the way, is it just me or is that room a lot like the color my wife had me paint our hallway upstairs?    I wasn't finished yet so switch plates are missing, I really should take a recent pic.
    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
  • steamheatnewbsteamheatnewb Posts: 14Member
    room color

    Thanks for the tip! I didnt realize these things could come apart to replace pieces.

    Rooms look like identical color combos! I am using Buckland Blue from Benjamin Moore... using the color in a couple rooms, looks great!
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