If you’re handy enough and confident you don’t need a plumber, we’ll explain how to replace a water shut-off valve on a copper pipe. This valve is a handy device that connects water supply lines to sinks and toilets. Closing it can isolate a leak without turning off your home’s entire water supply. It’s not used often, yet it wears out over time. Here’s an overview of how to change one so it’ll work when needed. For more information on replacing a toilet shut-off valve, follow our link to that article.
Determine What Type of Valve You Have
The incoming copper pipe and the size of the supply tube connection must match. Therefore, the type of valve matters. Water shut-off valves have either a compression fitting with a hexagonal nut that matches the hex flats on the valve body (or, two flats on the side of the valve), or a sweat fitting. A sweat fitting has no hex flats at the copper tubing entry point; this valve can be replaced with the same one or a compression valve.
Also, look for soldered connections. The fitting will have a smooth end near the pipe and silver solder around the joint. Other valves have a threaded connection to a copper or galvanized pipe. These must be replaced by a threaded valve. However, compression and soldered valves can be replaced with a compression type, solder-type, or push-to-connect stop valve.
Prepare to Begin Water Shut-Off Valve Replacement
Preparing to replace a shut-off valve requires just a few simple steps:
- Turn off the nearest in-line shut-off valve or the main water supply valve.
- Turn a gas water heater to the pilot setting.
- Turn off an electric water heater and its circuit breaker.
- Open a faucet on the lowest and highest floor to drain the line.
- Place a bucket under the valve to catch any remaining water.
Remove the Old Valve
Before you can replace a water shut-off valve on a copper pipe, you must remove the old one first. How to do so depends on the type:
- Sweat Valve: Holding the valve with pliers, loosen the nut, and unscrew the valve stem. Remove the old washer. Let any remaining water drain out. You’ll need a torch to remove the valve; use a flame protection cloth to protect the wall and have a fire extinguisher nearby. Set the torch on a small flame and aim it at the valve body until you can twist and pull it off the copper tubing.
- Solder-Type Valve: Sweat valves often have solder, which must be sanded off before you replace the escutcheon plate, nut, and sleeve. The supply line may need to be cut with a pipe cutter and deburred with a pipe deburring tool. If working in a tight space, use a propane torch to heat and loosen the fitting. Twist the valve with pliers to remove it from the pipe.
- Compression-Style Valve: Use an adjustable wrench to loosen the compression nut. With a second wrench, hold the valve steady while turning the other wrench clockwise. Remove the compression sleeve and nut and rotate the sleeve off the tubing. You can also saw off the sleeve if it’s stuck.
- Thread-Type Valve: Using a pipe wrench, hold the pipe steady. Twist off the valve with a different adjustable wrench.
Install the New Valve
Once the old valve is removed and the pipe opening is exposed, you can begin installing the new water shut-off valve. This requires the following steps:
- Prepare the Pipe: Sand the pipe and remove as much solder as you can if installing a solder-type or push-to-connect type valve. Before installing a compression-style valve, slide the compression nut over the pipe as far back as it will go. Then place the compression ring over the end of the pipe. For a thread-type valve, remove any remaining thread seal tape, clean the pipe threads with a wire brush, and wrap them in new thread seal tape.Â
- Install the Valve: The technique for installation depends on the valve type, so you’ll want to proceed as follows:
- Solder Valve: Place the solder-type valve onto the pipe, twist it, and evenly place the flux (use ½ inch of solder for every ½ inch of pipe diameter). Open the valve to avoid melting the washer. Using a propane torch, heat the fitting, apply solder when the flux starts bubbling, and clean the joint before the solder dries.
- Compression Valve: Thread the valve into the compression and make sure it fits snugly over the compression ring. Tighten the compression nut with an adjustable wrench while holding the valve with another wrench (turn it one-half to three-quarters of a turn or as the manufacturer suggests). Be careful not to overtighten the nut.
- Thread-Style Valve: Thread the valve onto the pipe by hand. Then secure the pipe with a pipe wrench and use an adjustable wrench to tighten the valve. Again, avoid overtightening it, as the valve or threads can be damaged.
- Push-to-Connect Valve: Press it squarely and evenly onto the pipe and then pull gently to make sure it’s locked (no tools are required). The fitting will form a watertight seal. Most valves of this type require at least an inch of stub-out tubing. Straight and angled valves are available depending on your pipe’s configuration.
Attach the Water Supply Line
Attach the pipe and supply line. If you’re reattaching the old lines, follow the same procedure as installing the valve. If using new braided flexible lines to replace the old supply, first remove the old line from the faucet and then connect the supply line and valve.
Inspect the Connection
Make sure the connection is watertight and doesn’t leak. To do this, turn on the main water supply and open the new valve. Open the tap to let the water start flowing. This will clear any air from the line. Touch the fittings or place a paper towel on them to check for leaks. If there’s any water or moisture, tighten the fitting slightly.
Frequently Asked Questions
How Long Does It Take to Replace a Shut-Off Valve?
Most shut-off valves are installed quickly. Newer ball valves can be installed in under an hour. However, the length of time the job takes depends on the condition of the old valve and the design of your plumbing system.
Can I Repair the Old Valve Instead?
Old valves can often be rebuilt. However, the problem you’re having will eventually return. Bad valves should be replaced with more durable quarter-turn ball valves, which are resistant to wear and rarely leak or lock up.
Is It Safe to Change a Shut-Off Valve Without a Plumber?
Hire a professional if you’ve never done this project before. It’s also best to let a plumber work with galvanized pipes in older homes. Rusted pipes or rotted threads can make the job more complicated.Â
Contact Sky Heating & Air Conditioning
Replacing a water shut-off valve is not easy for everyone. If you’ve never replaced one, the job seems more complex, or the pipe is rusted or damaged, we can help. Our plumbers are fully trained and licensed. They can determine the best valve type to use and address any issues they find. For prompt service in the Portland area by a technician who knows how to replace a water shut-off valve on a copper pipe, call (503) 308-7577 today.Â