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Is this 5 year old LGB-8 boiler cracked/leaking? Still searching for system leaks

bkc Member Posts: 37
In my post from 2022 I reported losing about 4 gallons of water per day from a church steam boiler system.

In the past 2 years I've gotten that down to about 2.1 gals/day (23-24 heating season) by tightening unions, replacing F/T faces with pinhole leaks and/or to stop steam-blow through that was then boiling out condensate tanks, etc.

We're still losing 2.1 gallons per day. During the summer I filled up the boiler (while cold) all the way to the top of the 'T' to which the pressure gauge, pressuretrol and overpressure cutoff are attached and let it sit for 2 weeks. The water level did not drop at all.

I'm stumped, where is the water going?

Its not possible for me to see steam going out the top of the chimney, its just too tall.

However today I took a quick look in the burner area and found at least two rust areas below what could be two leaks close together. I couldn't see any steam escaping from this location, but maybe its too slow to see.

Do you think this constitutes enough of a leak to justify replacing these sections? Its theoretically under warranty for 5 more years (parts only)

Thanks for any suggestions,

The red arrow points to a 1/4" tall metallic (or mineral) stalactite from which water must have been dripping for quite a while.

I suppose I should try to remove the burner shield to get a better look at the rest of the underside of the boiler.


  • Steamhead
    Steamhead Member Posts: 16,832
    I think it's leaking. But- you should be able to tell for sure by starting the burners and heating it up until it just starts to send steam into the header. Shut down the burners and check those places again.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
  • clammy
    clammy Member Posts: 3,111
    It most likely has been leaking from the day the block was assembled by the installer ,only if assembled all tappings plugged and pressure test would one be sure the block was assembled correctly if this was not done then i would gather its been leaking slowly from the start . This seems to happen alot being the expense and time of pressure testing a block might seem extensive from a installers point being most do not add time for such and most are afraid they will not get the job if there price is higher the rest of the pack . If the leak is at the field assembled portion of the block your outta luck being it was not the factory assembled portion of the block installer neglected to follow instructions . Even though weils are just o ringed and quite easy to assembly it basically just not following instruction and doing the pressure test just being lazy . the other issue may be your near boiler piping and lack of a swing joint but this usually cracks the block while your looks like its the o rings. hopefuuly your installer is still around ?
    peace and good luck clammy
    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating
  • Intplm.
    Intplm. Member Posts: 1,945
    It might be time for you to add something called boiler seal. It's a product when added to the boiler will stop leaks as you have described.
    You should consider this to be a temporary fix but will, when added properly, stop leaks.
  • bkc
    bkc Member Posts: 37
    @Steamhead Thanks for your comment. I took the photos while the boiler was at about 2psi.

    Should I expect a tiny stream of steam to not be visible? Maybe I should stick some paper under there and see what happens, or maybe wait until the boiler cools off to see if drops form?
  • pedmec
    pedmec Member Posts: 973
    You don't see it because the leak is below the water line or at the water line and probably leaking down when the boiler cools.