Adding a dishwasher to your kitchen may seem like an elaborate undertaking. After all, if your kitchen wasn't originally equipped with one, it means adding the pipes to support it. If you're considering doing the work on your own, you'll have to start by making sure your pipes are prepared. The first thing you'll need to do is replace the standard two-way valve under your sink with a three-way valve to accommodate the extra water outlet. Here's a look at what you need to know about three-way valves and how to install them.
What Does a Three-Way Valve Do?
Two-way valves are the standard plumbing valve for a traditional faucet, because these valves have a single outlet for water that routes directly to your sink faucet. The three-way valve, on the other hand, includes an additional water outlet that you can use to provide water to an additional appliance or fixture, such as a dishwasher.
How Do I Install a Three-Way Valve?
The three-way valve must be installed correctly to avoid the potential for leaks and serious water damage in your home. If you don't have the plumbing expertise to do this properly, talk with a local plumber about doing the work for you. Otherwise, here are the steps to install a new three-way valve in your kitchen:
Remove the Current Valve
Before you do any work on your plumbing, turn off the water supply to the sink. This ensures that the pipes are free of water before you remove the valve. Then, place a bucket directly beneath the valve to catch any residual water in the lines.
Use a faucet wrench to loosen the compression nuts on the pipe that runs between the valve and the faucet. Remove those nuts and pull out the riser pipe, which is the pipe between the sink and the valve. Then, use a tubing cutter to cut the supply line as close to the edge of the valve as possible. Aim for a straight, smooth cut so you can get a good fit on the new valve.
Install the New Valve
Place a new compression nut on the cut end of the supply pipe. Then, place a ferrule in the compression nut. Put the three-way valve in place, securing the ferrule against the threads. In most cases, the new compression nut and ferrule will come with the valve, but you can buy them from any plumbing supply store as well. Tighten the compression nut on the cut pipe until it is hand-tight, which means you cannot tighten it anymore by hand.
Install the riser pipe that runs from the valve to your sink faucet, securing each side with the compression nuts. In most cases, the old riser pipe will fit without a problem, but if it doesn't fit, measure the distance from the compression nut on the valve to the sink pipe so that you can choose a new pipe that fits properly. Secure both ends of the riser pipe with compression nuts, then go back and secure them using a faucet wrench.
Measure the distance from your dishwasher's input valve to the output of the three-way valve. You'll need to get a water pipe that length or cut flexible tubing to fit. Then, secure each end with the same compression nut and ferrule combination. Once everything is secure, turn on the water and check for leaks. If there are any problems, call a local plumber (such as one from Archie Johnstone Plumbing & Heating) to help you troubleshoot it.