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water level on glass gauge

The gas steam boiler is 4 years old and has a Cycle Guard with indicator lights.

The water level was 1/2 inch from the top of the glass viewer when I removed the weekly amount (until it runs clear) but after taking out a significant amount of rusty water the glass gauge remained in the same position from top even though I was refilling it slowly at the same time.

I let is stand for about an hour and when I came back the level was 1/4 of the glass viewer. Added more water this time faster since the boiler was cooler, but still the level only increased to 1/3, so I let it stand for another 2 hours and when the thermostat turned the boiler on, the radiator valves started hissing (never did before), so I run to check the boiler and noticed water was dripping  from one of the 6' pipes that ends on the air valve; so I turned the thermostat down and the power off.

A couple of hours later I returned to find the glass viewer topped off. Tried removing some water again but the LWCO guard yellow light turned on, so I filled it until it went off and the green lit up and turned off a few seconds later. I finally left it alone overnight powered off.

Still on the second day the glass gauge is toped off so I kept the thermostat at 62 so it doesn't run too often. I don't know if this is logical or not, but rather be cold than have the boiler break.

I was advised to open the up and lower valves of the glass gauge all the way (they were slightly onpen). Also, to remove the water gauge glass and its fittings and clean out the connections, all the way to the internal boiler. The same for the low water cut off device.

Thanks for any clue you can give me as to why the water is still topped off on the gauge even though the boiler has been working. Thank you!


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    Confusing water level

    Have you now cleaned out all the passages of the gauge glass? Are the top and bottom valves (gauge cocks) open? What is the pressure of the system now?. Has any recent maintenance been performed recently?

    High pressure from a clogged pigtail may be forcing water out of the boiler up into the dry returns to the main vent location.--NBC
  • new2mesteam2013
    new2mesteam2013 Member Posts: 2
    water level on glass gauge

    I haven't cleaned the glass gauge components yet, but did open the valves as far as they'll go yet no water drained from it.  And ,other than removing and refilling every week in the winter and once a month in the other months I have not done any other maintenance. What do you advice needs to be done and how often?

    Due to this issue I started looking into the boiler upkeep and will be buying the "We got steam heat" book, but now I need to know what to look for when I call in a professional to service it.
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