January 20, 2015

How a water softener works

By Sears PartsDirect staff
How a water softener works.

A common misconception about water softeners is that they add salt to hard water to soften it. While salt is used in the water softening process,  it’s the removal of hard water minerals—not the addition of salt—that makes the water soft.  Understanding how a water softener works can help you identify the cause of any problem that might occur.

A water softener has two operation cycles; the water softening cycle and the resin regeneration cycle.

Softening cycle

Hard water from the main water supply flows into the water softener, passing over resin beads located in the resin tank. The positively charged hard water minerals are attracted to the negatively charged resin beads, causing the hard water minerals to stick to the resin. The water leaving the water softener is now soft and ready to use.

Regeneration cycle

Over time the resin beads become coated with the hard water minerals and must be cleaned. The resin beads are washed by a strong salt water–or brine–solution. The sodium in the solution forces the hard water minerals to detach from the resin beads. These hard minerals are then flushed, and the resin is ready to collect the hard water minerals again.

Testing your water

Not sure whether your water softener is doing its job? This Sears PartsDirect video shows how to test your water. Also, check out our water softener DIY repair help page for step-by-step instructions in repairing your water softener.

Symptoms for water softeners

Choose a symptom to see related water softener repairs.

Main causes: broken resin tank screen, bad resin tank seals, cracked upper distributor in resin tank
Main causes: faulty brine valve assembly, bad rotor valve
Main causes: clogged drain hose, faulty rotor valve, leaky rotor valve seals
Main causes: lack of electrical power, bad power transformer, faulty timer
Main causes: loose water line connections, cracked water-carrying components, bad rotor valve seals
Main causes: empty salt tank, salt bridge, depleted resin, clogged or damaged venturi, broken rotor position switch, failed timer
Main causes: salt bridge inside the salt tank, bad timer, valve motor failure, faulty rotor valve, clogged venturi
Main causes: broken water flow meter, faulty timer, water flow to softener is bypassed
Repair guides for water softeners

These step-by-step repair guides will help you safely fix what’s broken on your water softener.

How to replace a water softener rotor position switch

The rotor position switch detects the position of the valve rotor. If the rotor position switch fails, follow these steps to replace it in about half an hour.

Repair difficulty
Time required
 30 minutes or less
January 1, 2015
By Lyle Weischwill
How to replace a water softener venturi

The venturi draws brine water from the salt tank to the resin tank for regeneration. Follow these steps to replace a damaged venturi.

Repair difficulty
Time required
 15 minutes or less
January 1, 2015
By Lyle Weischwill
How to replace a water softener valve motor

The valve motor rotates the valve rotor to operate the water softener. If the valve motor fails, follow these steps to replace the valve motor.

Repair difficulty
Time required
 30 minutes or less
Articles and videos for water softeners

Use the advice and tips in these articles and videos to get the most out of your water softener.

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Water softener common questions
By Sears PartsDirect staff

Find answers to some of the most commonly asked questions about water softener repairs.

January 20, 2015
How a water softener works
By Sears PartsDirect staff

Learn how a water softener works to provide your home with soft water.