In this video, This Old House plumbing and heating contractor Richard Trethewey refurbishes an old water softener.
1. Remove the control head from the water softener and pull out the tank.
2. Dump the old resin beads from the tank, and flush the tank clean using a garden hose.
3. Place new manifold tube inside of tank; temporarily seal top end of tube with piece of electrical tape.
4. Dump several inches of gravel into tank; fill remainder of tank with resin beads.
5. Remove tape from top of tube, then thread new control head onto manifold tube.
6. Install a new valve onto the control head.
7. Make plumbing connections joining cold-water supply to tank, and water-supply line to the house.
8. Install a second tank next to the water softener, and fill it with blocks of sodium to create a brine solution.
9. Make the pipe connections joining the brine-solution tank to the water softener.
10. Connect the discharge hose to softener.
11. Once all connections are made, turn on the water and check for leaks.