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Water in Gauge Glass Keeps Going Up

HeatingHelp Administrator Posts: 635


  • amcauley
    amcauley Member Posts: 4
    I am having the same issues, my sight glass keeps filling up and I have turned off the water line into the system. I have even as gone as far as to turning the boiler off entirely. Water somehow fills up the site glass. I continuously drain the radiators 4 buckets in the morning and 4 in the evenings. I am still trying to figure out how water is still filling up in a system that is off and I have my automatic feeder working properly. Have you discovered what the issue could be to stop the overfilling?
  • 109A_5
    109A_5 Member Posts: 1,385
    Hello @amcauley,
    Unless you have an abandoned DHW coil in the boiler leaking (looks like you have a NG fired DHW heater tank), a manual bypass fill valve or the valve for the automatic filler is leaking.

    You should get the sight glass leak repaired, it promotes additional water addition which will shorten the boiler's life, fresh water bring in Oxygen promoting corrosion.

    Pictures of the auto feeder system ?

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,818
    edited March 19
    You should start your own Discussion @amcauley. Your photo and your problem show that you do not have the same setup as the original post from over a year ago.

    If you have read all the comments and they have not answered your questions, then we should start for scratch. Perhaps @Erin Holohan Haskell can create a new thread titled Water in Gauge Glass Keeps Going Up.

    We will need answers to some questions

    1. Does your steam boiler provide both heat (radiators) and Domestic Hot Water (showers)
    2. Did it ever provide DHW in the past?
    3. Do you have a separate water heater?
    4. Does your steam boiler have an automatic water feed?
    Just to start with.

    More questions to follow.

    Can you post some photos from farther back so we can see the pipes that connect the boiler to the radiators. so we can see the boiler and connecting pipes from floor to ceiling, and from at least two different sides.

    EDIT: I just looked at the file photo. It appears that your boiler is connected to the radiators with copper tubing. Not the best choice by the installer, but it may be fine. I see a separate water heater, so a leaking tankless coil is not your problem.

    How long have you experienced the problem? Is it a new condition, or have you always had this issue?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • Erin Holohan Haskell
    Erin Holohan Haskell Member, Moderator, Administrator Posts: 2,279
    Thanks, @EdTheHeaterMan!

    @amcauley, I've created a new discussion for you here to prevent confusion.
  • Jamie Hall
    Jamie Hall Member Posts: 23,272
    To state the obvious. If the water in the sight glass is going up, you have water being supplied from somewhere. Now...jtrace every possible water pipe that can allow water to enter the boiler. Every single one. Find all the valves on the pipes. Turn them all off. Water still going up? Either one of the valves is leaking by, or you haven't found them all. Now to be fair, I may say that finding a valve which is leaking by a very small amount can be a real bore...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,818
    I wonder if @amcauley is still having this problem?
    Is there a chance that a feed valve is passing? even if the valve is completely closed but some water ls still passing, like a dripping faucet might be completely closed but a drip still happens. All you would need to fix this is a new valve that does not pass a little drop of water even when completely closed.

    If you are a decent DIY kind of person, this will be no problem for you. If you do not have the skill set to replace a leaking valve, then a plumber would be in order.

    From the looks of the boiler in the attached file, It was not the best installation I have ever seen. Copper riser indicates that the installer does not have a full understanding of how steam boilers work. Those installers that do understand steam, always use threaded steel pipe and iron fittings.

    I hope you find your answers @amcauley
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics