Guides
How to Install a Water Softener
To install a water softener, shut off the main, fit a bypass on the main line, connect inlet and outlet the right way round, run drain and overflow lines, then add salt and start a first regeneration. Budget a few hours.
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Quick answer
- Mount it on the main line, ahead of the water heater.
- Fit a bypass valve so you can isolate the softener.
- Match inlet and outlet to the arrows on the valve.
- Leave an air gap where the drain line discharges, per local code.
- Program your hardness, then run one manual regeneration.
| Item | What to expect |
|---|---|
| Time | SoftPro states 2 to 4 hours with basic plumbing tools for its Elite; QWT states about 2 hours for the Fleck 5600SXT |
| Skill level | Comfortable cutting and joining your pipe type (copper, PEX or CPVC) |
| Needs nearby | Main water line, a floor drain, standpipe or laundry sink, and a standard outlet |
| Usually included | Bypass valve on many systems (SoftPro Elite and ECO include one) |
| Pro install cost | Typically about $200–$1,000; see our cost guide |
| Rules that apply | The maker's manual and your local plumbing code |
Plan the location
Plan the location before you buy fittings. The softener belongs on the main line after the well pressure tank or the water meter, and ahead of the water heater so hot water is softened too. Many installers leave outdoor hose bibs on hard water to save salt; that means tapping in after the outdoor branch.
Pick a level, dry spot that stays above freezing, within reach of a drain and an outlet. Leave room to pour salt into the brine tank and to reach the valve.
On a well with iron, sulfur or acidic water, any filter or neutralizer goes before the softener. SoftPro states its AIO iron filter installs upstream of the softener, and QWT describes it going after the pressure tank. Sizing comes first; check our sizing table before you order.
Read the manual end to end before you cut anything. Valve drain ports, brine fittings and programming menus differ by brand, and the manual's instructions override anything general here.
Installation steps
Tools and materials: tubing or pipe cutter, two adjustable wrenches, thread seal tape, fittings for your pipe type (push-fit, PEX crimp or sweat), deburring tool, bucket and towels, drain tubing with clamps, a grounding jumper kit if your pipes are metal, hardness test strips, and clean salt pellets or crystals.
- Turn off the water heater. Set gas units to pilot or switch off power to electric units so they do not heat while the supply is off.
- Shut off the main and drain the lines. Open a low faucet and an upper faucet to relieve pressure and empty the pipes.
- Set the tanks in place. Stand the resin tank and brine tank on a level surface. Some systems ship with resin loaded; others need the riser and media added per the manual.
- Cut into the main and fit the bypass. Install the bypass valve on the control valve, then run pipe or flexible connectors from the main line to it. Keep connections square and unstressed.
- Check inlet and outlet orientation. The supply line goes to the port marked IN and the house side to OUT; follow the arrows. Reversed connections can push resin into household plumbing.
- Bond the pipes. If metal water pipes are part of your electrical grounding, add a jumper across the softener so the ground path stays continuous.
- Run the drain line. Connect tubing to the valve's drain fitting and route it to a floor drain, standpipe or laundry sink. Clamp it and keep it free of kinks. Where it discharges, leave an air gap as your local code requires, so dirty water can never be siphoned back. Respect the maker's limits on drain length and height.
- Run the brine tank overflow. Connect a separate line from the overflow elbow to a drain. It works by gravity, so it must run downhill from the fitting, and it must not tee into the valve drain line.
- Connect the brine line between the brine tank and the valve, then add salt and any water the manual specifies.
- Repressurize slowly. With the bypass set to bypass, open the main and check every joint. Then move the bypass to service a little at a time, letting air escape through a cold faucet.
- Program the valve. Enter time of day and your hardness in gpg. Add about 4–5 gpg per ppm of ferrous iron. Set the salt level per the manual.
- Run the first regeneration. Start a manual cycle, watch for leaks, and confirm water flows from the drain line during backwash. Afterward, test hardness at a cold tap and switch the water heater back on.
Plug the valve into a standard outlet, ideally one not controlled by a wall switch. If your valve needs a GFCI outlet or a dedicated circuit, the manual will say.
Install errors that cause callbacks
Hard-piping the drain into a sewer line
No air gap means a backflow risk and a likely code failure.
Teeing the overflow into the drain line
Under pressure, the valve drain can back up into the brine tank.
Skipping the grounding jumper
Cutting metal pipe can break your home's ground path.
Opening the water too fast
A rush of water can disturb the resin bed and trap air.
Related guides
Common questions
Can a homeowner install a water softener?
Usually, if you can cut and join your pipe type and your town allows owner plumbing work. Some areas require a licensed plumber, a permit or an inspection, and some restrict softener discharge, so check before you start.
Where should the drain line go?
To a floor drain, standpipe, laundry sink or other approved receptor, with an air gap at the outlet. Never connect it directly to a sewer pipe, and keep it within the maker's length and height limits.
Does a water softener need its own outlet?
Most electronic valves plug into a standard 120V outlet. An outlet that stays on all the time is best, since a switched outlet can stop the clock and the meter.
How long before the water is soft?
After the first regeneration finishes, water at the taps should test soft. Pipes and the water heater still hold some hard water, so flush them by running hot and cold taps for a few minutes.
Should the softener go before or after a whole-house filter?
Sediment, iron and acid filters go before it. On city water, a carbon filter usually goes ahead of it to protect the resin from chlorine.
Choosing a DIY-friendly system
Choose a system built for DIY: a pre-installed bypass, quick-connect fittings and clear video instructions make the job far easier. Our best whole-house water softeners roundup ranks the SoftPro Elite Smart HE first, followed by SoftPro ECO and the Fleck 5600SXT, and notes what each one includes in the box.
Comparing options? Start with our best water softeners and reviews.