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Radiator Vents Question

Hello, everyone. This place has been a great resource for me. I have a couple of questions.

1. Do radiator vents usually fail closed or fail open? If they fail open, how can I tell? Will there be visible steam coming out? The reason I ask is because some of the vents hiss and gurgle while some other don't. So, I don't know if the vents are actually broken. The ones that hiss are Maid O Mist's.

2. My vents on the ground floor are mostly Gorton #4's. The radiator vents on the 2nd floor are mostly Gorton D's. But, the radiators on the 2nd floor still doesn't get as hot as the radiators on the 1st floor. And, it gets cold up there. What can be causing this?


  • Rod
    Rod Posts: 2,067
    Radiator Vents

    Hi - In my experience radiator vents fail open, usually after sitting all summer.   The best way to test them is to hold a strip of newspaper in front of the vent hole. If it moves, then air /steam is passing through the vent.  If the vent is working you should be able to detect a sudden stop in the flow of the air when steam reaches the vent.  Live steam is invisible. you can only see steam when it starts to condense. DO NOT check the vents using just you hand! Steam burns aren't fun!

    You can try removing stuck vents (with the boiler off and cool) and boiling them on the stove in a pan containing  white vinegar as  this sometimes un sticks them.

    Have you main vents been inspected /replaced recently? What make/model are you using for main vents?

    - Rod
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