How to Plumb a Water Softener

Updated: Oct. 31, 2023

Branch off cold water lines to outdoor faucets before running the cold water through the water softening system.

water softener installation water softener installation, how to install a water softenerFamily Handyman
The plumbing hookups on a water softener can be confusing, but we'll show you how the connections should be made. You don't have to be a plumber to connect a water softener. We make it easy to understand even for a beginning DIYer.

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Water softener installation

The plumbing around a water softener can be confusing when attempting to learn how to install a water softener. A cold water branch before the water softener doesn’t necessarily indicate a problem. It’s standard procedure to branch off one cold water line to supply outdoor hose connections (and sometimes another to the kitchen sink and refrigerator icemaker if you don’t want to drink softened water).

Water for gardens and lawns doesn’t need to be softened. The main supply line to the rest of the house continues on to the softener. Once the water leaves the softener, it should branch into two lines: a cold line that runs to interior fixtures and faucets, and a line that feeds the water heater. The outgoing line from the water heater then runs to interior fixtures and faucets that dispense hot water. In addition to those lines, there should be a soft water bypass loop (shown in the photo) with a valve you can open to bypass the softener if you need to disconnect it temporarily without disturbing the water supply to the house.

Required Tools for this water softener installation Project

Have the necessary tools for this DIY how to install a water softener project lined up before you start—you’ll save time and frustration.

  • Plumbers tape
  • Slip joint pliers
  • Soldering torch
  • Tape measure
  • Tube cutter

Required Materials for this water softener installation Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here’s a list.

  • Copper pipe
  • Copper tee
  • Fitting brush
  • Flux
  • Solder
  • Valves