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.