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Leaking System

mpc469 Member Posts: 3
We have a one pipe steam system that is constantly losing water when running. It needs to be filled every other day. When system is shut down for summer the water level will completely drain down within a 2 or so weeks. System has a hartford loop, low water level shut off. No visible leaks. My return does go under basement floor. No water stains on floor where line runs. Where could my problem be?
Thanks in advance


  • Steamhead
    Steamhead Member Posts: 16,841
    edited November 2019
    Could be the boiler itself. A leak above the waterline will send steam up the chimney, and you won't see it on the floor.

    That underground return is probably leaking too, but not as fast as the boiler might be.

    Where are you located?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    HVACNUT Member Posts: 5,841
    Losing water when shut down in summer. There is a leak(s) in the wet return. Not seeing a stain doesn't mean it's not there. Plan on a repipe.
  • Jamie Hall
    Jamie Hall Member Posts: 23,310
    Probably that we return -- but your comment "drains down completely" also suggests a leak in the boiler or one of the low fittings on the boiler, as the Hartford Loop should limit the loss from the wet return.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • mpc469
    mpc469 Member Posts: 3
    I have been told the wet return would probably be the issue or one of the issues. It just did not make sense that it would drain down with the hartford loop. I was under the impression that it would keep water in the boiler no matter what unless I have an issue with the boiler itself leaking. I'm located on Long Island NY.
    Thank you for the comments
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,839
    You may have more than one leak.
    I'm picturing an old coal conversion with a combustion chamber on the floor with lots of insulation (Vermiculite) around the chamber, absorbing the water leak in the boiler section(s) so you don't see any water stains on the floor (OR NOT)

    need more info.. pictures will help all us
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics