Trickle down gauge glass

V8toilet_3

The waterline should slowly move up and down 1/2-3/4" and there should not be any water trickling down from the top of the gauge glass. This indicates that the water inside your boiler is fluctuating too much because of contaminated water or too high of a PH and still needs to be skimmed. It took me a whole month of skimming before I got all the oil and crap completely out of my new boiler. Make sure that the PH of the water is in the range that your manufacturer recommends and that your pipes are insulated. Maybe you should post a picture of the near boiler piping for us to see.


A test some guys perform to see if the quality of the water in the boiler is good is to close off the valves to the gauge glass and drain the water in the gauge glass while the boiler is steaming. I then open only the top valve with the drain caulk open at the bottom of the gauge glass. If the boiler water is good all you'll see come out is a little bit of water vapor as the steam coming out condenses in the cold air. If you see water come over the top of the gauge glass than the boiler needs cleaning.

David Nadle

Is a little trickle ok?

I've had the new boiler skimmed twice, and there's definitely been a big improvement. Right now, after an initial surge or two when water just begins to steam, the waterline fluctuation in the gauge glass is pretty stable, about an inch.

There is still a small trickle down the top of the glass. My inclination is that this is OK given that the waterline is pretty steady and the glass above the waterline is otherwise clean and dry. Am I right, or should I expect absolutely no trickle down the glass?