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Scale on Boiler

tms1989 Member Posts: 1
Hey all, I’ve noticing scale buildup lately on the outside of my boiler. Not sure what it is but it’s got me a bit worried. I attached a picture. Any response is appreciated!


  • nicholas bonham-carter
    Is this steam or hot water?
    It looks like moisture from somewhere has evaporated leaving behind calcium.
    When you can turn off the boiler for a day, you can try the overfilling test to see if there are any leaks, (steam).
    If it’s hot water, it may be condensation from the water being not hot enough, as a result of a faulty acquastat.—NBC
  • RayWohlfarth
    RayWohlfarth Member Posts: 1,555
    It looks like that is a water to water heat exchanger perhaps for domestic hot water? I think the flange may be leaking. I would brush it and try snugging the bolts a quarter turn and watch it. You may need a new gasket and it could be done in the summer.
    Ray Wohlfarth
    Boiler Lessons
  • the_donut
    the_donut Member Posts: 374
    I can’t tell for certain from that picture, but it looks like copper goes to steel without a dielectric union. That can cause corrosion from dissimilar metals.
  • JohnDag
    JohnDag Member Posts: 1
    I had the same issue some time ago but after doing some research, I located a company out of Germany called Wellan 2000. They have a rep here in the U.S. I can't remember the company name but I used one of their devices which isn't powered and it's not a magnet. I haven't had to use any chemical treatments or do any yearly replacement of tubes since the installation. You guys can search it on google and let me know how you make out.
    EBEBRATT-Ed Member Posts: 15,840
    Its you tank less water heater gasket as @RayWohlfarth mentioned.

    Wait until summer as it's possible the bolts will be difficult to remove