In this video, This Old House plumbing and heating expert Richard Trethewey visits New Jersey to install a water softener.
1. Turn off the water at the meter.
2. Use a tubing cutter to tap into the existing cold-water pipe.
3. Connect the water softener's resin tank to the cold-water pipe by soldering on an assembly of copper pipe and three valves.
4. Run a length of ⅜-inch-diameter plastic tubing from the resin tank to the salt tank; connect each end of the tubing with compress fittings.
5. Use a hose clamp to attach the drain line to the drain elbow on the resin tank.
6. Install an air-gap fitting to the drain that leads to the sewer pipe.
7. Attach the water softener's discharge hose to the air-gap fitting with a hose clamp.
8. Hook the discharge hose from the washing machine onto the air-gap fitting.
9. Fill the salt tank with salt.
10. Turn the water back on.