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Water level glass always full.

heater40 Member Posts: 6

I have a gas furnace used on steam heating and also a water feeder attached I don't know what's going on but the glass for the water level is always full to the point where it isn't below the glass at all whether the furnace is on or off it's always full so I was wondering what I should do or what I could do to lower the water level both knobs top and bottom above the water level glass are both open and I was thinking maybe the water feeder might need an adjustment I don't know but I'm a little worried and concerned. Can someone help?


  • ethicalpaul
    ethicalpaul Member Posts: 5,735

    Your autofeeder is allowing too much water into your boiler, which could be for a variety of reasons.

    Do you know where the drain is for your boiler? Your water level might be even higher than the top of the glass, there's no easy way to know until it starts shooting out of all your radiators, then you'll know.

    It would be good to drain enough water out until you can see it 1/2 way up the gauge glass.

    You said they were open, but make double sure the valves on the gauge glass are open or you won't be able to see when the water is lower.

    Then call in a professional, or if anything I have said isn't very clear to you just call a professional first. But if you are handy at all you should be able to drain the boiler enough to see the water level, then you can watch to see if the water level goes up by itself and how fast it does, while you wait for the pro to come.

    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • heater40
    heater40 Member Posts: 6

    Hello both knobs on glass are completely open I do know where the drain for my boiler is and I have that one point drained out enough water like you said to have like a half an inch or a little bit below the glass showing I have a feeling the water feeders putting too much water into the furnace so if I make adjustments to the water feeder settings would that be a bad thing to try?

  • Jamie Hall
    Jamie Hall Member Posts: 23,438

    What adjustments — if any — there are for the feeder depends entirely on what make and model feeder it is. Can you provide that information?

    In the meantime, I would suggest closing the manual shutoff on the boiler makeup water line and let the boiler run for a few days — but keep a close eye on the water level. You shouldn't see any rise at all after the boiler cools after a cycle is done — nor you should the level fall much over a few days.

    If the water rises, somewhere water is leaking into the boiler that shouldn't be getting in, and we will need to have more information to figure out what. If it falls, somewhere in your heating system there is a leak — and we need to find and fix that.

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • neilc
    neilc Member Posts: 2,707

    any chance the boiler is used to make domestic hot water?

    the domestic coil could be leaking back to the boiler,

    post pictures if you're not sure

    known to beat dead horses
  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,106
    First off, it's a boiler,  not a Forced Air furnace.  The first you need to have checked is the Gauge Glass Cocks...they very likely could be clogged and not showing true level.  This can very tricky for a DIYer and HO and even inexperienced plumbers once you add an auto-feeder in to the mix.  Find a Contractor here and have him come put for full service of the water/steam side. Mad Dog 🐕