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forced HW heating system

Dave_4 Member Posts: 1,405
How long does the water hammer sound go on for?


  • James McQuaid
    James McQuaid Member Posts: 3

    I have a forced HW heating system with monoflow tees. When the system is heating there is a loud water hammer through the piping. what causes this and what are the solutions. I do not believe air is the problem. Thank you.
  • Steve_35
    Steve_35 Member Posts: 546
    Two common things

    If the pipe is copper and is clamped right to the joists you will often get a VERY loud hammer. Most often the straps are metal. Copper expands a lot and the metal clamps pinch it in place until enough expansion has taken place and it lets loose.

    The other thing that sometimes happens is when you have multiple zones and fast acting zone valves are used. One ZV closes while there's a call for heat in another zone. The valve slams shut and can make a bang. That's usually a single bang.
  • James McQuaid
    James McQuaid Member Posts: 3
    HW heating

    The piping is 1 1/4 screwed the hammer starts a few minutes after the boilier starts to heat and doesn't stop until the t'stat is satisfied.
  • Techman
    Techman Member Posts: 2,144

    Can you determine if the noise is comming from the boiler or somewhere in the piping?
  • Uni R_2
    Uni R_2 Member Posts: 589
    Spring Loaded Flow Check?

    Do you have a spring loaded flow check valve?
  • Daniel Staring
    Daniel Staring Member Posts: 2
    Forced Hot Water and adding hydroair unit for my basement

    I have a Forced Hot Water boiler with three zones in my 1st and second floor of my home and need heat from my basement. While I have baseboard radiators upstairs that work great I do not care for them much as they get in the way. We refinished the basement as a play room and would prefer not to have baseboard heaters installed as kid typically step on them and otherwise dent them.

    Can we install a hydroair wall unit? If so how much should this cost? The finished basement is about 500 sq feet.
  • James McQuaid
    James McQuaid Member Posts: 3

    There is no check valve and it seems as though the hammeris coming from the piping but it may be from the boiler.
  • differnt thread

    Seemed like this a different problem than the first thread... For the guy with hyrdo air, ur best bet is to go to Cast Iron Baseboard...
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