How Often Should a Water Softener Regenerate?

What regeneration does

The resin beads in the softener hold onto calcium and magnesium until they're full. Regeneration flushes them with brine from the salt tank, which strips off the hardness and sends it down the drain, as Minnesota's Department of Health describes. Then the beads are ready to soften again.

A typical cycle has several stages: backwash to loosen the bed, a brine draw, a slow rinse, a fast rinse, and a refill of the salt tank. On the Whirlpool WHES48, the brine draw can take 15 to 20 minutes to show a visible drop in the tank. Hellenbrand lists one model's full cycle at about 57 minutes with a normal backwash, so cycle length varies a lot by model.

Do the math for your house

Penn State Extension's example is the clearest way to see it:

• A family of four uses 75 gallons per person per day, so 300 gallons a day.
• Their water is 10 gpg hard, so the softener removes 3,000 grains a day.
• Their softener holds 20,000 grains between regenerations.
• 20,000 divided by 3,000 is about 6 to 7 days between regenerations.

Run the same math with your own numbers. Multiply daily water use by hardness to get grains per day, then divide your softener's capacity by that. If the answer is under about three days, the softener is small for the house. HomeGuide sizes softeners for 3 to 7 days between regenerations, and our softener sizing page shows how.

Timer vs demand (metered) softeners

How the softener decides when to regenerate matters as much as the schedule.

A timer softener regenerates on a fixed schedule whether you used water or not. Minnesota's pollution agency points out that on timer systems, regeneration isn't tied to usage. If you go on vacation, it keeps cycling and using salt.

A demand-initiated (metered) softener counts gallons and regenerates only when the resin is close to full. Morton calls this demand regeneration and says it regenerates only as needed. Even metered units usually have a maximum days setting as a backstop. Whirlpool's allows 1 to 15 days, and Hellenbrand's day override allows 1 to 28.

If you have a timer model and your usage changes a lot, a metered control is the better long-term setup. A Waterloo, Wisconsin, ordinance goes further and requires demand controls with a minimum efficiency of 3,350 grains of hardness per pound of salt.

How to tell if yours is cycling right

• Note the regeneration time. Many softeners default to a 2:00 in the morning start. A wrong clock means cycles while people shower.
• Check salt use. If it's far above the usual couple of bags every month or two, regeneration is too frequent or the hardness setting is too high.
• Test water after the softener just before a scheduled regeneration. If it's hard, the softener is running out of capacity too soon.
• Watch the brine tank during a cycle. Whirlpool's manual says you should see a noticeable drop in the liquid level during the brine step. If the level doesn't drop, the softener isn't drawing brine.

Each regeneration also uses water. Penn State estimates about 50 gallons per cycle, and Whirlpool gives 44.2 gallons at its maximum salt dose. Regenerating twice as often doubles that.

How to regenerate a water softener manually

Run a manual regeneration after adding salt to an empty tank, after cleaning the brine tank or resin, or after a hardness setting change.

On most digital controls you press and hold the regen or recharge button for a few seconds. On the Whirlpool WHES48, holding RECHARGE starts it immediately, and a quick press schedules it for the next set time. Hellenbrand works the same way: hold REGEN for 3 seconds to start right away, and once started it can't be canceled. Older mechanical timers usually have a dial you turn to the start position.

Avoid hot water during the cycle. Whirlpool notes that the water heater would refill with unsoftened bypass water.

When regeneration problems need a fix

If the softener never seems to regenerate, the salt level never drops, or water stays hard right after a cycle, the cause is usually a clock, a salt bridge, a clogged injector or a failing control. Start with water softener not regenerating and check your hardness setting.