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Valve spitting

DK27 Member Posts: 28
I just installed new vari valves on my heating system. I have a mix of mostly cast iron radiators, and 3 single pipe baseboards w/ fins.  There is one single pipe radiator in my bathroom that spits lots of cold water as the system heats up, and then the valve won't close when it gets hot losing all it's heat quickly.  I suspect that maybe the condensate isn't draining properly and the valve isn't closing when it does get hot. Has anyone else encountered this problem and found a fix?  Is there a better valve that closes when "wet"?



  • Big-Al_2
    Big-Al_2 Member Posts: 263
    edited October 2011
    VariValves Spit

    Varivalves seem to spit more than any others.  There are three reasons for this. 

    First, the vent will allow the radiator to fill with steam very quickly.  Having big open vents even on all of the radiators means that there is nothing holding the steam back anywhere, and often one radiator will get the lion's share of early steam, creating gobs of condensate that gets carried along with the rush of air coming out of that big open vent.

    Second, the outlet of the Varivalve isn't much higher than the inlet.  It doesn't help the water in the vent drain back into the radiator very well, and doesn't present much of of a barrier for that water to get blown out the next time the system comes on.

    Third, Varivalves don't have any kind of float in them. Unlike most vents, if they get flooded with condensate, they will still open up and spit it out.

    I had three of them on various radiators and gave up on them, switching to Gorton or Maid-o-Mist vents.   After one season with containers under them to catch their drippings, I sold them on eBay for a fraction of what I paid for them.  If you don't want to waste your investment in VariValves, you might first try  closing them all up about 75% shut.  Then if you find a radiator that's slow to heat up, you can open that vent uo to half.  It doesn't totally overcome the inherent design problems, but it should help.

    Maid-O-Mist vents are my favorite.  They are like Gortons, with a bimetal actuator, but they have removable orifices that can be removed and enlarged if necessary.  They are quiet and fairly inexpensive too.  Some say that they are not as durable as Gortons, but I haven't had issues with either, and I own both.
  • DK27
    DK27 Member Posts: 28

    Thanks big al, i'll try switching to a different valve and see how that works out.  Appreciate the quick response.
  • Rod
    Rod Posts: 2,067
    Vari Valves

    Hi- I agree with Al on the Vari- Valves   Iniatially I thought,  "Great !...Use big radiator vents and the radiators will heat faster!". It doesn't quite work out that way as they can really screw up steam distribution.   The old steam guys have an adage: "Vent your mains quickly and your radiators slowly!"  I'm sure there are a lot of guys like myself who have tried Vari Valves and now have them collecting  dust on a basement shelf. They do have their uses but only in isolated situations.

    - Rod
  • ChrisJ
    ChrisJ Member Posts: 15,671

    The four heat timer vents I had are now in my neighbors basement mounted on his mains as vents.  Down in his basement theres far less damage spitting can do than over my wood floors.  I went to Hoffman 1As on all rads.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
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