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Lime deposit on pipe Why

acl10 Member Posts: 349
edited February 2019 in Strictly Steam
Why is there a white powdery substance forming on one of my pipes. It is on the pipe that goes from the main pipe of the boiler into the return. It is also forming on the opening of the low water cutoff valve Mcdonall Miller 67. It seems like a lime deposit. The boiler is located in Brooklyn NY so we have NY water and I had put in the boiler Rectorseal 68712 Quart 8-Way Boiler Water Treatment at the beginning of the season



  • Intplm.
    Intplm. Member Posts: 2,090
    That looks like a leak that has "healed". It will need to be repaired eventually.
    EBEBRATT-Ed Member Posts: 15,849
    I agree
  • gfrbrookline
    gfrbrookline Member Posts: 753
    Looking at pic 2 I am not sure it has healed.
  • Fred
    Fred Member Posts: 8,542
    @gfrbrookline , I thought the same thing about picture #1. The threads on the vertical pipe looks wet to me.
  • gfrbrookline
    gfrbrookline Member Posts: 753
    @Fred agreed on pic 1.
  • acl10
    acl10 Member Posts: 349
    If its a leak woudnt it be rusty? Why the lime deposits?
    Why the lime deposits on the opening of the low water cuttoff. Does my boiler water have to be treated?
    I checked I dont really feel a leak it may be a little bit caused by the pipe moving a bit when the new water heater was installed. What should I bit around the pipe to seal it?
  • ethicalpaul
    ethicalpaul Member Posts: 5,802
    You know it's lime? It's on the wet return it looks like, so it could be from some old boiler treatment chemical? Or something else, but I think no one has any doubt that the drip pattern shown can only be from a leak.

    I wouldn't trust some kind of substance applied to the exterior of the pipe to fix this. I would replace the pipe and any others that looked like it this summer.

    I can't see enough of the low-water cutoff pic (is that the last one?) to give an opinion about it, but it could have been from the LWCO being blown out for maintenance?

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  • pecmsg
    pecmsg Member Posts: 4,968
    It could be an small old leak that sealed itself or a a major issue waiting to happen.

    Get the pipes replaced!