Handyman Tip:

How to Replace Under-Sink & Toilet Shut-off Valves

As a Phoenix and Chanlder Arizona handyman, I spend a lot of time under sinks. This article describes replacing Under sink and Toilet Shut off Valves

Step 1.  Shut off the water at the main water valve.

Step 2.  Inspect the valves you are preparing to replace.  How are they attached to the house water line pipe?  The pipe coming out of the wall is typically 1/2” rigid copper pipe.  If you observe anything other than copper pipe, I recommend calling a professional.  Ok, you have determined the water pipe is copper.  Now you have to determine how the valve is attached to the pipe.  Is the valve soldered to the pipe?  If it is, are you comfortable working with a propane torch under your sink?  Is there several inches of copper pipe between the wall and the valve?  No, it is time to call a professional.  Yes, then there is an option to using a propane torch. 

2A.  If you have several inches (at least 3”), you can cut off the valve immediately behind the valve with a hacksaw.  Clean the end with emery cloth inside and out to remove any burrs.  Proceed to step 2B or 2C.

2B.  Is the valve attached with a compression fitting?

Your valve is attached with a compression fitting if you look behind the valve and see a large nut on the copper water line.  To remove the valve, hold the valve with adjustable pliers.  Loosen the nut with a adjustable wrench.  Once the nut is loose the valve will pull off the pipe.  The nut and compression ring will remain on the copper pipe.  Rush the nut back on the pipe and clean off the compression ring with a rag.  Is the ring whole and not pitted?  If so it can be reused.  Is the nut whole, not cracked or pitted?  If so it can be reused.  If no to either question, cut the pipe behind the compression ring, dispose of the compression ring and nut.  Clean the end  of the pipe with an emery cloth, inside and out.  Take the old valve with you to the Home Center or Hardware Store and pick up a replacement.  Slip the new nut onto the pipe, threads facing the valve.  Slip the compression ring on after the locking nut, then slip the Teflon tape on valve threads valve on.  Hold the valve with an adjustable pliers and tighten nut with an adjustable wrench.  Repeat this process for other valves.

2C.  Is the valve attached with a push-lock or shark bite fitting?

Your valve looks like it is just sitting on the pipe.  This is probably a “push-lock” or sharkbite fitting.  At the back of the valve do you see what appears to be a plastic washer “O” ring?  You will need a special decompression tool.  This device looks like a plastic letter “C”.  It is sold at home centers and hardware stores for a dollar or two.  Slip this tool over the copper pipe and squeeze it against the valve, at the same time pull the tool and valve off the pipe.  The tool releases the “Teeth” inside the fitting allowing it to slide off.  Take the valve to the store and pick up a matching valve.  To install the new “push-lock” valve, mark off 1” on the pipe.  Push the new valve onto the pipe until the valve is on at least 1”. Turn on the main water valve.  Reattach faucet or toilet waterline and turn on valve.