Glass Bottom
What do the red knobs on the top and bottom of the sight glass do?
Hi
I am flushing my water but I noticed that the sight glass's water level changes only when the red knob at the bottom of the sight glass is open. What does it do? Should I leave it open when I am not correcting the boiler's water level?
Thanks
You can leave it open ….it I just a indicator of water level.
Because water seeks it’s own level…… when you open the bottom one you are getting a true reading of the water in the boiler.
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