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New Boiler or Repair it!

GB142 Member Posts: 16
edited September 3 in THE MAIN WALL
I have been on here over 16 years and have always found the comments on the Wall helpful.

I have a 2005 Vintage GB142/45. It is still running well and looks like new, thanks to a few new electrical parts. However, I have developed a small leak in my HX. Based on the picture, can anyone tell me if this is a leak of glycol or a leak from the condensation?

GB142/45 HX can still be purchased. I have no idea how much it costs to install them, but given the modularity and ease of access with the unit, I hope not too much. If anyone has replaced one, can you provide an approximate amount of time it takes? Other parts are still available and since my unit is still in great shape, this is my preference.

My initial discussions with an installer familiar with Buderus, suggested I look into replacing my GB142 with a boiler made by IBC would be expensive. I have never heard of IBC.

Here's my 16-year-old unit and the small leak.


  • mattmia2
    mattmia2 Member Posts: 3,429
    Please remove pricing.

    I don't know enough about how that HX is assembled, but is that leak in the HX itself or just a gasket?
    Erin Holohan Haskell
  • Steamhead
    Steamhead Member Posts: 14,700
    mattmia2 said:

    Please remove pricing.

    This. Go here for the FAQ:
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Erin Holohan Haskell
  • GB142
    GB142 Member Posts: 16
    edited September 3
    Pricing removed. The gaskets are top and bottom of the unit. These gaskets are used for gaining access to the HX for cleaning. So the leak is not from them.

    However, you raise an interesting question based on the location of the leak.

    There is silicon in that seam where it is leaking. I assume this is high temp silicon. If just silicon, can the old be removed, then a new bead installed?
    Erin Holohan Haskell
    EBEBRATT-Ed Member Posts: 9,394

    Could be a leak, could be condensate.

    You could raise the boiler pressure up a bit and see if the "leak" gets worse. Or disconnect the piping and pressure test the HX.

    You can probably buy just the HX. Then you would have to decide if the labor cost outweighs the price of a new boiler.

    Yours looks like new.
  • GB142
    GB142 Member Posts: 16
    I opened up the unit over the past few days to run several cleaning procedures with the mineral oil. My heat exchanger is now clean.

    After examining the HX and location of the leak, it does seem to be coming from within HX chamber and is the result of condensate coming out of the seams, which have been sealed with High-Temperature clear silicon.

    I plan to pick out the old silicon with a dental tool then lay the new silicon. I purchased LavaLock clear 650, which is good up to 650 degrees. Can anyone confirm for me that this will be sufficient for both within the HX chamber and on the outside?

    Lastly, can anyone tell me how long it usually takes to replace the HX if that is the direction I end up going?

  • mattmia2
    mattmia2 Member Posts: 3,429
    You will probably need to remove those through bolts and disassemble the headers from the core and put the new silicone between the surfaces then clamp/press it back together, just squeezing it in from outside isn't likely to work.
  • pecmsg
    pecmsg Member Posts: 2,130
    At 16 years replace it!
  • kcopp
    kcopp Member Posts: 3,771
    With all that goes into assembling a boiler...all the asme certifications and all is it really worth it? God forbid if something happens and new you have to explain to an insurance company that the boiler was tinkered with. Something to think about...