Buried pipe leaks...

nybigapple

Steam boiler is still losing a sight glass of water in a day. This is after fixing a burst pipe. I've looked all around the cellar and there is no leaking. No tenants have said anything about leaking and I'm guessing the leak has to be quite noticeable if it was in the walls or at the radiators.

I did the overfill test on the boiler, though I did not wait long after. I simply overfilled into the dry run pipes. Waited about 10 minutes, and saw no water. Someone else mentioned the fact that the system could easily reach 5 psi aids the idea that there probably is no leak in the boiler. I've looked at the chimney and also do not see billowing white smoke.

This leaves the worst case scenario of buried courtyard pipes. 25-30 feet long steam pipe to a rear building with another pipe for the wet return. They are both buried in 10+ ft of concrete on either side of the courtyard. Digging them up seems prohibitively expensive. What is the expected outcome of not fixing the pipe and living off the water feeder?

Are there alternative piping options that ignore pitch in a steam system? Like laying new pipe and using a pump?

Another option off the top of my head. I would think disconnecting the two buildings would also be a better option. Putting a separate steam boiler in the rear building's cellar for just the rear building.

Does it sound like I'm missing someplace else for the leak?

BobC

With a thermal imaging camera any leak in concrete should be locatable, you just have to find a pro that knows how to do it. It's probably easiest to do when heat is n regular use.

If you elect to just go with the auto water feeder the leak will just get worse and the boilers life will be dramatically lowered. That leak has to be found and fixed.

Bob

SWEI

BobC said:

With a thermal imaging camera any leak in concrete should be locatable, you just have to find a pro that knows how to do it. It's probably easiest to do when heat is n regular use.

Leaks become most obvious when the system is recovering from a deep setback. To maximize contrast, lower the thermostat to 55°F the afternoon of the day before. The next morning, raise the thermostat to 80°F, wait about 30 minutes, then pull out the IR camera and look for hot spots.

New England SteamWorks

Based on the conditions of the other piping in your system, I'd say it would be highly unlikely that the underground returns are not leaking.

All that fresh water will kill your boiler, so all leaks need to be found and fixed.