How To: Install an Under Sink Water Filter
Discover how to quickly and easily purify your water by installing an under-sink water filter with expert tips from David Hunt, a master plumber of 35 years.
Everything you’ll need for the installation:
- Water Filter Installation Kit (any brand)
- Tongue and Groove Pliers
- Drying Rags
- John Guest 3/8 in. LLDPE Tubing
- John Guest Polypropylene Push-fit 3/8 in. Elbow
- John Guest Polypropylene Push-fit 3/8 in. Female Connector
- SharkBite PRO PEX Cutters
Installation
Under-sink water filters provide easy access to filtered water and are simple to install. For this application, make sure your water filter kit is NSF and IAPMO approved and has an IN and OUT label on the sides.
To start, examine the setup of your sink and determine where you’d like to place your water filter. Then, shut off the water supply on the cold side of your sink. Once the water is off, disconnect the cold water supply line and thread the John Guest Polypropylene Push-fit 3/8 in. Female Connector on, then tighten the connection with your pliers.
Next, look for the IN and OUT markings on your water filter, as these labels will help you keep track of the direction of the water flow. Then, screw the water filter into place under your sink and check that it is secure. To connect the
Use your SharkBite PRO PEX Cutters to evenly cut the John Guest 3/8 in. LLDPE Tubing and push one side into the female connector on the cold side. Then, use the pipe cutters again to cut the pipe as needed and push the other side of the pipe into the side of the water filter labeled IN.
Then, take the cold water supply line and thread on a John Guest polypropylene push-fit 3/8 in. female connector, securing the connection with your pliers. Once the supply line is prepped, push a John Guest Polypropylene Push-fit 3/8 in. Elbow into the side of the water filter labeled OUT. Then, cut piece of the LLDPE tubing, a few inches in length, and use it to connect the elbow to the female connector.
After making all your connections, turn the water supply back on slowly and check for leaks.