Fleck (Pentair) · Water Softener error code

Err 4Piston not where the control expects

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Related diagnostic guides

Guide · Water Softener

Softener not regenerating

A softener that never regenerates usually has a drive problem (motor, gears, stuck piston), a programming problem, or a meter that is not counting. Error codes on Fleck and Clack valves point straight to the drive.

5 steps ~60 minmoderate

Guide · Water Softener

Hard water returning (softener has salt but water is hard)

Most hard-water callbacks come from salt that is not reaching the water (bridge or mush), wrong settings, or a regeneration that is not drawing brine. Check the brine tank first, then programming, then the valve.

5 steps ~45 mineasy

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Softener regenerates at the wrong time (often after a power outage)

Most timer and metered controls schedule regeneration by the clock, typically in the middle of the night. After an outage the clock can be wrong or reset, so regenerations happen when people are using water. The softener still softens, but the clock and settings need checking.

4 steps ~20 mineasy