The Water Softener Regeneration Cycle

The stages in order

During normal service, resin beads in the softener tank trade sodium (or potassium) for the calcium and magnesium in your water. Over days, the beads fill up with hardness. Regeneration rinses the resin with salty brine from the brine tank, which pushes the hardness off the beads, then flushes the loosened minerals and leftover brine to the drain.

The Fleck 5600SXT manual gives the order for a single-backwash downflow valve:

1. Backwash (BW). Water flows up through the resin bed, the reverse of normal service. It lifts and loosens the bed and carries trapped sediment out to the drain.
2. Brine draw and slow rinse (BD). The valve's injector draws brine out of the brine tank and passes it slowly through the resin. This is where the hardness comes off. When the brine is used up, fresh water keeps moving slowly through the bed to push the spent brine out.
3. Rapid rinse (RR). Water runs quickly down through the bed to repack it and flush out the last of the brine, so the first water you draw isn't salty.
4. Brine tank fill (BF). The valve sends a measured amount of water back to the brine tank, where it dissolves salt for the next regeneration. On a Fleck SXT, this refill is set by the BF time rather than a float.
5. Service. The valve returns to normal softening.

Twin-tank systems do the same steps but alternate tanks, so one stays in service while the other regenerates and the house has soft water around the clock.

How long it takes

SoftPro's reset guide gives a full manual cycle 60 to 90 minutes from start to finish. The exact length is the sum of the step times programmed into the valve.

The Fleck 5600SXT accepts anything up to 199 minutes per step, plus an OFF value. In the manual's terms, a zero skips only the one step, but OFF ends the cycle there and cancels the steps that follow. The Fleck manuals don't list factory default step times. Quality Water Treatment's install guide shows the times it programs:

The guide's SST-60 settings change only the backwash, rinse and refill, so the brine draw stays at 60 minutes. Quality Water Treatment notes that the refill time depends on system capacity. Use the times in your own valve's paperwork rather than copying another system's.

Each cycle also uses water: roughly 50 gallons a time, by Penn State Extension's estimate. That's one reason to avoid regenerating more often than needed, and something to weigh on a septic system.

How often. A well-sized softener on a lean salt dose should land near one cycle per week. Store guides give intervals from every 2 to 7 days depending on hardness and water use, and Penn State's worked example, four people on 10 gpg water, comes out at 6 to 7 days. The full method is in how often a water softener should regenerate.

Metered vs timed

The control decides when to regenerate in one of two ways.

Metered (demand) valves count the gallons that pass through a flow meter. When the soft water used reaches the calculated capacity, a regeneration is due. The Fleck manual describes two metered modes: meter delayed (Fd), which waits for the set regeneration time, usually overnight, and meter immediate (FI), which starts as soon as the capacity runs out. A day override still forces a cycle if the set number of days passes first.

Timer (time clock) valves regenerate on a fixed schedule, every so many days (tc on a Fleck SXT) or on chosen days of the week (dAY), whatever the water use. They regenerate even when the household is away, and can run short when usage spikes.

Metered valves tend to use salt and water more efficiently, because they regenerate based on actual use. Capacity, reserve and regeneration time are set in the control; the settings guide explains each value, and the control valve guide covers the valve types.

What's normal to hear and see

A regenerating softener makes some noise, and most of it is normal.

• Water running to the drain. Backwash and rinse send water down the drain line for much of the cycle. If the drain line runs into a laundry tub or floor drain, you'll see and hear it.
• The valve moving between steps. A Fleck SXT blinks its step number each time the piston travels to the next position.
• The service icon flashing. A cycle is waiting for tonight's start time.
• Flow indicator flashing. This shows water is flowing through the meter.
• Hard water during the cycle. On a single-tank softener, water drawn during regeneration bypasses the resin. That's why the cycle is scheduled when no one is using water.
• Brine level changes. The brine tank water level drops during brine draw and rises again at refill.

Some things are not normal. The Fleck manual's troubleshooting table lists a drain that flows continuously as a sign the valve isn't positioning properly, has debris in the control or has an internal leak. A brine tank that keeps filling up, or salt that never goes down, points to a brine draw problem; see brine tank full of water and water softener not using salt.

To watch a cycle on a Fleck SXT, press Extra Cycle once to queue it for the regeneration time, or hold it 5 seconds to start one right away. Pressing it again during a cycle moves to the next step. If the clock was reset by a power cut, follow how to reset a water softener first.

Related guides

• SettingsHardness, iron and reserve settings
• SettingsPicking a regeneration interval
• SettingsThe 5600SXT display and menus
• FixWhen salt level never drops

Common questions