Water disappearing from sight glass before boiler even turns on

bpthomas

Hi, My thermostat is off, as we won't need heat for another few weeks. I inspected by gas powered steam boiler and tried to manually add water. I opened the valve and there was a long delay before the water level went up on the sight glass but it finally did. I came back an hour later and the water level was all the way back down. I repeated this and same thing happened. There are no visible leaks so where could the water be going? Again, this boiler isn't even on so its not steam loss. I do notice brown gunk and the within the bottom of the sight glass.

JUGHNE

Do you have any wet returns....pipes under the floor?
If so can you isolate them from the boiler with a valve?

Pictures please if you are not sure.

Jamie Hall

Significant leak somewhere. If you have no wet returns, or a Hartford loop, it's got to be in the boiler. Which is not good news.

nicholas bonham-carter

Are you sure the boiler is empty?
A full gauge glass can look empty!
look for water on the floor.
if the wet return pipes are under the floor, a leak can go unnoticed. Replacement runs can run above the floor, but well below the waterline, for ease of replacement-NBC 

EBEBRATT-Ed

As others have mentioned look for wet returns ...pipes run under the cellar floor.

If no wet returns I would take of the water gauge glass and make sure the gauge glass connections to the boiler are clear, The water level may be fooling you.

bpthomas

Thanks everyone! It does seem like I was being fooled by inaccurate sight glass. I took it apart and flushed out all the liquid rust and things seem to be working now.

JUGHNE

Did you clean the pigtail also.....