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Radiator air vents filled with water

I have a one pipe system, boiler about 15 years old. this is our first winter in the new house. I found two radiator vents with water in them, one on the first floor, the other on the third floor. Not much movement in the level glass when the boiler is on, all the other radiators work normally. Does that mean simply that the two air vents failed open and filled with condensate?


  • BobC
    BobC Member Posts: 5,408
    edited March 2011

    It could be that but check the radiator and the pipis that feed it to be sure they are sloped back towards the boiler.

    If the air valves are stuck open try boiling them in white vinigar for 15-30 minutes to clyar the calcium deposits.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Daveonepipe
    Daveonepipe Member Posts: 4

    thanks BobC
  • Big Ed_4
    Big Ed_4 Member Posts: 2,361

    You may also want to invest in better vents .. I recommend a slow adjustable float type with a tongue . The tongue helps drain out the valve , the float will help contain an over filed boiler and the slow adjustable is to tame, control and help balance the system .
    I have enough experience to know , that I dont know it all
  • Daveonepipe
    Daveonepipe Member Posts: 4
    thanks Big Ed

    Big Ed, I switched in Heat Timer Varivents and adjusted them based on radiator size. So far so good. the old vents were maid o mist jacobus, and others of that type have failed this year, just failed closed instead of open, so it was an easier conclusion to reach.
  • Big Ed_4
    Big Ed_4 Member Posts: 2,361

    Varivents are non float types and vent way too fast... Slower is the way to go in a residential home .. Varivents are for apartment buildings
    I have enough experience to know , that I dont know it all
  • Daveonepipe
    Daveonepipe Member Posts: 4


    I don't doubt what you say, they are much faster than the maid o mist vents. I have them all adjusted down towards the closed side, but for one very large radiator that had a Maid o Mist "D" aperture previously. All the radiators get steam at about the same time now, the boiler runs less and there is no noise except the sound of air leaving the vents. I am not touching them unless something goes wrong. Thanks for the answer though.

    BTW, the main vents are both Gorton 2s. They are new as well.
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