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Excess water

and if the vents are working properly (i.e.: open as vacuum breakers) the waterline of the boiler should be the waterline of the system. My guess is that your system is holding some vacuum by virtue of inoperable vents.

Say, this would not be Pat from Marblehead, would it?


  • Pat_17
    Pat_17 Member Posts: 23
    How much water should be in the steam system?

    When the system isn't running and the sight glass is half full should there be any water in the return leading to the boiler? I always seem to have water backing up to my main air vent which is at the end of my main.How much water should be in the returns line when the system isn't running?
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