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Spitting Air Valve on Radiator

I recently purchased an old house with single pipe steam radiators. I keep having an issue with one radiator spitting water from the air valve. I pitched the radiator, put a new on/off valve, and air vent on but still water spits. Any thoughts on what to do to stop this. It looks like the issue has happened for some time as the floor and wall have damage. Any thoughts on how to stop this?

I am using Vent Rite No. 1 air valves that are set to 10. Also the on/off vent is all the way open. 

I have read that the issue could be the main vent, but my system has no main vent that I can see in the basement. 

Any help would be greatly appreciated. 

Comments

  • bburd
    bburd Member Posts: 1,059
    edited December 2023
    First, try turning the air vent to a lower setting.

    If that doesn't fix it, see if you can gently lift the radiator with a lever and fulcrum and slide some short wood blocks under the legs. Be careful so as not to crack anything. Possibly the building has settled and disturbed the pitch of the pipes, which should allow any standing water to drain back toward the boiler.

    If you can, check the pipe pitch from that radiator's run out back to the main or return.

    Bburd
  • Neild5
    Neild5 Member Posts: 184
    On the front of the boiler are controls, one is mounted on a pigtail, a spiral twisted pipe.  Please post a picture of it and the rest of your boiler.
  • BobC
    BobC Member Posts: 5,505
    edited January 6
    Try dialing the vent down to the midpoint and see if the spitting changes, venting a radiator too fast can induce spitting. In general you want to vent steam mains very fast and radiators slowly.

    Are there any spots where main vents may have been in the past?

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • kflory
    kflory Member Posts: 36

    I recently purchased an old house with single pipe steam radiators. I keep having an issue with one radiator spitting water from the air valve. I pitched the radiator, put a new on/off valve, and air vent on but still water spits. Any thoughts on what to do to stop this. It looks like the issue has happened for some time as the floor and wall have damage. Any thoughts on how to stop this?

    I am using Vent Rite No. 1 air valves that are set to 10. Also the on/off vent is all the way open. 


    I have read that the issue could be the main vent, but my system has no main vent that I can see in the basement. 

    Any help would be greatly appreciated. 
    When I had a spitting rad, the problem was my condensate return was too high and water was backing up into the rad. I had the return lowered closer to the floor and the problem was solved.