- Remove the water softener's 3/4-inch drain plug, usually located near the water intake pipe. Turn the plug counterclockwise with an adjustable wrench until it spins freely, then spin the plug with a hand.
- Cover the water-softener drain fitting's last three threads with a pipe thread compound or plumber's tape. A water softener's drain fitting has threads on its 3/4-inch side and ribs on its 1/2-inch side.
- Position the drain fitting's threads against the water softener's drain hole and twist the fitting clockwise. Hand tighten the drain fitting.
- Twist the drain fitting one full turn clockwise with the adjustable wrench. Do not over tighten the fitting.
- Locate a suitable code-approved drain opening, using local building codes as a guide. Many water softeners dump waste water into a clothes-washing machine's drain pipe, while other water softeners use a floor drain. Some homes are pre-plumbed for a water softener and use a 1/2-inch pipe penetrating the wall near the floor as a water softener drain connection.
- Push the end of a 1/2-inch braided drain tube onto the water softener's drain fitting. Push the end of the tube onto the 1/2-inch end of the drain fitting until it passes the ribs and butts against the back of the 3/4-inch side of the fitting. The rib locks the tube in place.
- Run the tube to the suitable drain opening and cut the tube to size with a knife. If the end of the tube slips into a clothes-washing machine's drain, extend the drain 8 to 12 inches down the drain opening. If the tube connects to a pre-plumbed drain pipe, force the end of the tube over the drain pipe's fitting until it passes the pipe fitting's ribs. If the water softener's drain tube dumps into a floor drain, run the tube to the floor drain.
- Secure the water softener's drain tube with pipe hangers. Mount the pipe hangers to the wall or floor every 2 to 4 feet with screws. The type of screw depends on the wall or floor's material. Generally, drywall screws work on walls and wood floors. Concrete or tile floors need a pilot hole drilled and a concrete screw installed. Concrete screws come packaged in a kit with the appropriate size drill bit. Drill the pilot hole with an electric drill equipped with the drill bit supplied with the concrete screw kit.
How to Install a Water Softener Drain
A water softener's drain must not connect directly to a home's drainage system without an air gap between the end of the water softener's drain line and the home's drain system. The air gap eliminates the possibility that a negative pressure in the water softener will suck sewer water into the softener's storage tank. If a break occurred in the water-supply pipes, the negative pressure created from the water flowing out of the softener's tank pulls whatever the drain line connects to into the tank. Water softeners need a drain line installed for the tank's routine maintenance.