How is a water softener installed?

The location rules are the part most likely to trip up a do-it-yourself job, because they decide everything downstream.

• On the main line, before the water heater. The EPA guide says to make sure the softener "is installed on the home's water supply line before water enters the water heater." Morton says the same: "Always install the water softener between the water inlet and water heater."
• Ahead of the outdoor connections. The EPA guide advises avoiding softening water used for irrigation by installing the softener "after the plumbing line branches off to the exterior hose bibb or irrigation line." Morton says outside faucets "should remain on hard water to avoid wasting conditioned water and salt."
• After a whole-house filter, if there is one. The EPA guide says that if you have a whole-house filter, "it's generally recommended that you install your softener on the water line after water leaves the filter, so that any chemicals or sediment is filtered before softening." Morton likewise says other water conditioning equipment goes between the water inlet and the softener.
• Out of freezing and heat. Morton says not to place the softener "where freezing temperatures occur" and not to treat water over 120 degrees F, and warns that freezing or hot water damage voids the warranty. It also says to avoid direct sunlight, because excess heat "may cause distortion or other damage to non-metallic parts." That matters for a Valley garage or an outdoor wall. Our page on where to put a softener far from the water main compares the layouts.

The softener connects with an inlet, an outlet and a bypass. Morton's manual lists the pipe types it accepts on the inlet and outlet: copper, threaded pipe, PEX, CPVC and "other pipe approved for use with potable water."

A bypass valve is a standard part of the job. The Fleck manual says to "always provide for the installation of a bypass valve if unit is not equipped with one." The bypass is what lets you take the softener out of service without shutting off the house. The EPA guide says to use it when watering the lawn, washing a car or filling a pool, since bypassing the softener saves salt. Our page on where the bypass valve is and how to use it walks through the common designs.

One caution from Morton applies to any pipe work near the unit. It says not to solder with plumbing attached to the single bypass valve, because "soldering heat will damage the plastic valve." Plumbers solder fittings before connecting the valve for that reason.

The Fleck manual also gives supply limits to check before you begin. It calls for a minimum of 20 pounds of water pressure for the valve to work, and it says pressure is not to exceed 125 psi, water temperature is not to exceed 110 degrees F, and the unit cannot be subjected to freezing. Morton states its own minimum flow requirement of 3 gallons per minute at the inlet.

A softener discharges water every time it regenerates, so it needs a drain. Morton says a floor drain close to the softener is preferred, and lists a laundry tub or standpipe as other options. Its rules for the drain are specific:

• Air gap of 1-1/2 inches. Leave "an air gap of 1-1/2" between the end of the hose and the drain. This gap is needed to prevent backflow of sewer water into the water softener." The manual says not to put the end of the drain hose into the drain.
• Short and direct. Morton says to avoid hose runs longer than 30 feet and to avoid raising the hose more than 8 feet above the floor.
• Check local code. Flexible drain hose "is not allowed in all localities," and if your code does not allow it, a rigid drain line is needed.

The EPA guide adds a limit on where softeners can be used at all. It says some local jurisdictions prohibit ion exchange softeners because they discharge salt to the wastewater stream, so check local restrictions before you buy. Our page on whether water softeners work with Arizona hard water covers the Valley salt issue.

Morton's controller runs on 24-volt DC power from an included plug-in supply. The manual calls for a nearby 120-volt outlet that is in a dry location, installed to the electrical code. Plan the outlet before the unit arrives.

The start-up steps follow the same order in the Fleck manual. With the unit in the bypass position, turn on the main water supply, open a cold soft-water tap nearby, and "let run a few minutes or until the system is free from foreign material (usually solder) that may have resulted from the installation." Then place the bypass in service position slowly and let water fill the mineral tank. The Fleck manual then steps the valve through a backwash, a brine draw and a rapid rinse, and it says not to add salt to the brine tank at the early stage of start-up. Follow your own manual's order, since control valve types differ. Ask whoever installs the unit to show you the manual regeneration button and the salt level mark before they leave, because you will use both.

Morton's manual has a step for the water heater, too. It notes that the heater is filled with hard water when you start, so hot water becomes fully conditioned only as it is used and refills.

Some homeowners do install softeners, and the manuals are written with them in mind. The steps above are shared by the manufacturers, but the work involves cutting into the main supply, sweating or connecting pipe, and routing a code-compliant drain. Errors show up as leaks, hard water at the tap or a drain that backs up. The air gap is easy to miss, because a softener regenerates normally without one, but it is the piece the manual says prevents backflow of sewer water into the unit.

Some cities also treat the work as permit-controlled. Our page on the Scottsdale permit rule for softeners shows how one city handles it, and your own city's building department can tell you what applies to you.

Before you install, decide on size and salt. Our page on choosing the right size softener covers sizing, and how to maintain a water softener covers what the unit needs afterward.

HQ Plumbing & Air is licensed and insured. We can plan the connection, drain and bypass for your softener and install it. We offer free estimates and upfront pricing.