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Weil McLean Boiler Knocking

jojo4
jojo4 Member Posts: 5
I have a Weil Mclain gas boiler that's 15 years old.  It's been making a knocking noise when it cycles on (about every 30 minutes) that wakes me up two floors up.  It's quite loud.  I had a plumber put in 200x Sentinel but that didn't work.  It may be scale buildup but my question is this:  Would replacing a couple pipes with flex pipe contain the noise to the boiler itself so the noise doesn't travel throughout the house?  Has anyone else had this problem and tried this?

Thanks for any help.

Comments

  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    Hot water system?

    Is this hot water or steam?--NBC
  • Paul48
    Paul48 Member Posts: 4,469
    No Band-Aids

    You call in a heating professional to find and fix the problem. It may be less expensive than the solution you are proposing. Your system is warning you of a problem.
  • jojo4
    jojo4 Member Posts: 5
    Possible Solution?

    It is a hot water boiler.  Model CP3756177.  It is a professional who is suggesting this.  He wants to install 2 vibration isolaters. 
  • Paul48
    Paul48 Member Posts: 4,469
    I See

    It has always made this noise?
  • jojo4
    jojo4 Member Posts: 5
    No

    It started towards the end of last winter.  A plumber tried putting in the X200 a couple of months ago but it didn't help.  I've had several people look and no one can say for sure exactly what it is.  Someone from the gas company suggested pec (?) piping and now someone specializing in Weil Mclean is suggesting the flex pipes (2 vibration isolators).  This isn't guaranteed so just wanted to see if this solution had been heard of by anyone.  Four different professionals have said there is nothing wrong with the boiler itself or any of the piping.
  • Paul48
    Paul48 Member Posts: 4,469
    Details

    Can you give us some more details? Has it been determined the noise is coming from the boiler? Can you describe the knock....a series of rapid consecutive knocks....a single knock spaced out over a time?
  • jojo4
    jojo4 Member Posts: 5
    Sure

    The noise is definitely coming from the boiler towards the back.  It is singular successive knocking with about a second or two between each knock as opposed to a popping,  lasting approx. almost two minutes each time it kicks on.  It is not that noisy at the boiler itself in the basement but is extremely loud on the first floor and is also loud on the second floor.  It is not the baseboards.
  • unclejohn
    unclejohn Member Posts: 1,833
    Thats not

    The Mod.# Would be cga-6 or something like that.
  • unclejohn
    unclejohn Member Posts: 1,833
    Try

    Raising the pressure in the boiler by adding water and see if it stops. If it does you have a flow problem.
  • jojo4
    jojo4 Member Posts: 5
    Model

    It's a CG Series 12 boiler, if that helps (and thanks for the responses)
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,852
    Watch the pressure gage and see if it fluctuates

    with the knocking. It could be steam flash.



    I've seen castings where the casting sand didn't get completely cleaned out in the construction process, and it will cause this knocking, but usually shows up right away, not years down the road.



    Can you record it with your iPhone and send it to YouTube where we can watch and listen? Take a shot of the pressure gage while its knocking as well…



    As others have noted, raising the pressure may stop the boiling, if that's what it is.



    ME

    There was an error rendering this rich post.

  • M Lane
    M Lane Member Posts: 123
    Flex connectors

    are only going to mask the problem, if they work at all. Do you have a functioning air scoop/separator/vent? What does the pressure gauge do when the boiler fires? A flooded gravity expansion tank? Does the make-up water piping feel icy cold?

    Just slapping on crap is not the right way to deal with this. Boilers can become bombs if enough goes wrong.
  • knotgrumpy
    knotgrumpy Member Posts: 211
    Just curious

    " ...lasting approx. almost two minutes each time it kicks on. "



    What is the water temp when the boiler kicks on?  Is there a temperature gauge on it?