Remodeling Tips and Reviews

Replacing a cut off valve for the kitchen or bathroom sink

Replacing a cut off valve for the kitchen or bathroom sink

Dec 26, 2011

When remodeling a kitchen or bath one of the items that needs to be addressed  are the cut off valves for the water in the room. If they are leaky or are frozen from years of inactivity it is time to change them out.  The good news is there are several options that make this an snap.

First off as always, make sure you cut off the house supply line and open a low sitting valve such as your outside water supply to drain the pressure and water in the house.  Then it is time to open the valve that needs to be replaced and drain it out into a bucket or large bowl. Let it drain for a while. Once the water is done draining it is time to remove the old cut off valve. You likely have one of three styles, it will either be threaded on with a 1/2″ pipe, compression applied with a nut or sweated on with solder. For both the threaded and compression valves you should be able to use a cresent wrench or similar to remove the valve. You should use an adjustable wrench or a small monkey wrench to hold the pipe or nut in place while removing the valve. If that is not possible and the pipe comes off then you should take both to the store and replace them at the same time.  With the copper pipe you have 2 options. If you have a propane torch and know how to use it then you will want to heat up the old valve at the neck and use pliers to pull it off when it loosens. You may have to tap it firmly a few times to get it loose while you have to torch on it. You should also consider placing a fireproof piece of plumber’s clothe behind to prevent setting the surrounding area on fire. You are then going to need to carefully clean the extra solder off the pipe with a pipe brush, if there is water interfering with this, stick a piece of white bread in the pipe with a pencil to stop the flow.  The second option to remove the old valve is to simply use a small pipe cutter to cut the pipe as close as possible to the valve, you need to have enough room to do this as well as enough room to install the new valve.

drop the hot valve into water if possible to quickly cool it after you have used a torch to remove it.

1/4 turn ball valve with a compression head and a sweat base.

Once the valve is off you need to install the new valve. I recommend a 1/4 ball valve as opposed to the standard screw down valve. These cost a few dollars more, but are more reliable and don’t have a rubber washer that can wear out in a few years and result in leaky valves. You may want to consider changing the hoses at the same time if they show age and wear. No reason to save a few dollars and risk flooding your house because an old hose bust somewhere. When purchasing a valve you have to look at both sides to make sure you have the right one. It will need to be either threaded or sweat to attach to the house plumbing. The interface with the hose can be flared ( cone shaped) or compression. If you decide to replace the hoses then make sure they all match. Compression is used in most new application while flare was used in older homes with copper pipe supply lines. Another new option with copper pipes now is a slip on fitting that you simply push on the clean copper pipe and they stay put.

Reinstalling the valve is just the opposite of removal. If you have threaded valves, you will need to use teflon tape or plumber’s pipe dope to prevent water from leaking. If you are sweating the valve there are a few things that need to be done.

tip: If water keeps coming up the pipe towards your work you can try using a piece of white bread, it will dissolve and come out afterwards. If you are doing several of these then consider getting an air blower for a compressor and forcing air into the house lines.

  1. clean the old copper pipe thoroughly with plumbers sand paper til it shines and is free of old solder and corrosion.
  2. Using a plumbers 1/2″ cleaning metal brush, clean the inside neck of the valve.
  3. With a small brush apply flux to the pipe and inside neck making sure to coat both surfaces evenly but not too much.
  4. Place the opened up valve on the pipe and heat up the neck with your torch, do not heat up the pipe very much or the valve itself.
  5. Using a long piece of solder, start on one side and run it around the base of the neck until it is saturated, but before it starts dripping away from the seam.
  6. Allow it to cool for several minutes. Then close the valve and get ready to test.

Once you have tested the line for leaks, you should run the house water to flush out all the air.