Under Sink Anti Freeze Valve

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by xroad, Jan 17, 2009.

  1. xroad

    xroad New Member

    Oct 12, 2008
    Couple of years ago, I saw in This Old House magazine, I think, a valve attached under the kitchen sink water pipe. When the temperature drops to a low trigger point, the valve starts to drip. It is not a fast drip. It is a very slow drip. The slow controlled drip is sufficient to prevent pipe freeze. Please help me find it.

    I have a kitchen built on top of an enclosed porch. The underside of the porch was been enclosed with concrete blocks. The underside of the joists had been boarded up. Only access to the underside of the porch is a small basement window under the porch. Crawling in there is not an option.

    The cavities between the joists were not insulated. One of the cavity is used to run the hot/cold water and drain pipe. ONE time per year, after a few consecutive cold days, my water pipe freeze up. To clear the ice clog, I stick a hair dryer in the cavity from the basement and run it for 15 minutes or so.

    Last summer, I cut open the sink cabinet bottom, then cut open the kitchen floor under that, and reach the point where the water pipe turns up, through the floor and the cabinet bottom, into the sink cabinet. I lifted the pipe up an inch or so so they are not resting on the bottom of the cavity, where the other side is open cold air. In the created air space gap, I sprayed expanding insulating foam. Then, more foam to insulate the top side of the pipes. Then, finish up with fiberglass insulation to fill up the remaining space between the pipe and the joist and the back side (outside wall) of the cavity.

    I kept the 2.5 feet of joist cavity space between the foundation wall and the newly insulated area NOT inulated. My reasoning is that the warmer basement air will reach the exposed pipes. Had I inslate that portion, I would have isolating the pipes to the cold side as oppose to the warmer basement side.

    I was hoping this project will provide a delay of heat loss till a warm day comes along. Instead of 3 cold days to freeze, it may take 5 days to freeze. The likelyhood of 5 cold days is less than 3 days. Well, I think it worked. After a few days of very cold temperature, it freezed overnight. This time, it only took the hair dryer about 2 minutes to clear up the ice clog.

    BTW, I have split seam pipe insulation wrap on the pipes already.

    So, my project worked, but not 100%. I have been looking for the anti freeze valve for a while. Cannot find it.
    Last edited: Jan 17, 2009
  2. WV Hillbilly

    WV Hillbilly New Member

    Aug 1, 2008
    Did a quick google search & only found patent numbers for the kind of device you're looking for . Hopefully someone else will be more help .
  3. Sponsor

    Sponsor Paid Advertisement

  4. SewerRatz

    SewerRatz Illinois Licensed Plumber

    Nov 20, 2008
    Chicago Illinois Licensed Plumber
    Chicago, IL
    Sounds like someone took a trap primer and made it work when the temperature drops. You can call a insulation company that blows the insulation into the crawl area. I have had guys do this to outside walls of customers that had bad drafts going up the plumbing wall and freezing the pipes.
  5. xroad

    xroad New Member

    Oct 12, 2008
    This special valve I saw was specifically made for the purpose. It was not a piece together innovation by someone. I only saw the photo in the magazine. Too bad I did not write down the info.

    I may have to go to a library that have back issues going back one to four years.
  6. Scuba_Dave

    Scuba_Dave Extreme DIY Homeowner

    Jan 5, 2009
    Used to be in IT
    South of Boston, MA
    What about heat wrap?
    Insulating the pipes?
    My wife's old Condo had a problem with the pipe freezing under the sink. When it was going to be cold we would put a 100w light bulb on under the sink
  7. xroad

    xroad New Member

    Oct 12, 2008
    You took my thunder. I just thought of that last night. I cannot reach 2.5 to 3 ft into the joist cavity to put on an electrical heat tape wrap. The next most easiest thing is to stick a light bulb in there, shove it down deep with a stick and set it on with a timer. Turn it on between 12 midnight, when I go to sleep and 8PM when I get back from work. A 40F or so temperature switch would be ideal but it is not as easy to find.
  8. xroad

    xroad New Member

    Oct 12, 2008
    Dole Drip Valve

    I found something. Solar panel application and radiant floor heat application web site. Both mentioned Doe drip valve used for freeze prevention. Search of Dole valve came up with a few OTHER Dole valves, not the drip type.

    The Dole drip valve start to drip at 38F or 45F. $73 at http://www.thesolar.biz/SolarRoofs_Hot_Water_Collectors.htm
  9. xroad

    xroad New Member

    Oct 12, 2008
    For some reason, I was not comfortable with the electrical heat tape wrap, even if I can reach the pipe. I tend to like passive solutions. Besides, if the electrical fails, I would not know till it is too late. However, I am more comfortable with the light bulb solution since it gives me a visual indicator.
  10. CT

    CT New Member

    Jan 20, 2009
  11. leon

    leon New Member

    May 7, 2010
    mexico city
    thanks for the tip

    i think it is what i need
    best regards
  12. Gary Swart

    Gary Swart In the Trades

    Sep 1, 2004
    Yakima WA
    I think you are going to an extreme to solve this problem. First thing to remember is that insulation will not provide warmth. All it will do is slow heat transfer. Regardless of the amount of insulation, non flowing water will freeze if the temperature is below freezing for an extended period of time. In a fairly confined space such as under the sink, even a 25 watt light bulb will provide plenty of heat to keep the pipes from freezing. If the temperature is going to be cold for a fairly long period of time, you might well want to use a timer. If it is just a night to two, then you could just plug it in at night and unplug it in the morning. Disadvantage of that is you might forget! Well, maybe you wouldn't, but I would. LOL. I have to rig up a light under my dishwasher before next winter. My supply line froze during an exceptionally cold night last winter. Of course it warmed up so I haven't had to fix the problem yet. Hmm. Your question has inspired me to action. I'm on it today.
  13. cacher_chick

    cacher_chick Test, Don't Guess!

    Jan 5, 2008
    Test, Don't Guess!
    Land of Cheese
    Since I was little I remember being told to leave the faucet on enough to drip during the dead of winter. This past winter one local community put out signs telling people to leave their faucets drip so the pipes don't freeze.

    Seems to be a simple solution if your cost of water is not excessive.
Similar Threads: Under Sink
Forum Title Date
Plumbing Forum, Professional & DIY Advice Under sink pipes and dishwasher drain question Oct 5, 2017
Plumbing Forum, Professional & DIY Advice Extreme rust under sink faucet handles Oct 1, 2017
Plumbing Forum, Professional & DIY Advice Leak under bathroom sink Aug 28, 2017
Plumbing Forum, Professional & DIY Advice proper AC condensate connection under sink Aug 2, 2017
Plumbing Forum, Professional & DIY Advice Installing two 3-stage under-sink water filters in parallel for better flow Aug 2, 2017

Share This Page