Water Softener Troubleshooting, Step by Step

Start with the easy checks

These five checks need no tools and no parts, and they rule out the simplest faults first.

1. Power. The Fleck 5600SXT service manual says the valve needs an uninterrupted AC supply, and Pentair's 5600SXT manual says not to use a switched outlet. Check the plug, the adapter and any breaker. After an outage the time of day flashes; press any button to stop it and reset the clock, because a wrong clock means regenerations run at the wrong hour.
2. Bypass position. On a Fleck plastic bypass the knobs sit in line with the inlet and outlet pipes in normal service. Quality Water Treatment's install guide warns that a bypass not fully open can let hard water through. A push-pull bypass, per SoftPro, is pulled out for service. Other bypass styles have their own markings.
3. Salt. Lift the lid once a month. Pellets belong higher than the brine, with the tank about a quarter to half filled; where your manual names a different level, follow it.
4. Before-and-after test. Test raw water from an outside tap or the line before the softener, then softened cold water from a kitchen tap. SoftPro's guide says a wide gap between the two means the resin is doing its job. Use the same kit for both samples.
5. Water heater. The Fleck manual's troubleshooting table lists hardness held in the hot water tank as a cause of hard water after a repair. Test cold water first, and if only hot water is hard, flush the heater repeatedly. Turn off the heater's power or gas first, beware of scalding water, and follow the heater maker's instructions.

Salt and brine problems

If the easy checks pass but the water is still hard, the brine side is the next suspect. The resin only recovers if the valve draws salty water out of the brine tank during regeneration.

Salt bridge. Pellets can fuse into a shelf that hangs above the water, leaving plain water underneath. Pentair notes the valve keeps cycling while the resin gets no real recharge. Its fix: crack the shelf with a broom handle, give it 2 hours to make brine, run a regeneration, and repeat once if the water stays hard. Full steps are on the salt bridge page.

Mushing. Sludge at the bottom of the tank blocks the brine pickup. SoftPro says to empty and clean the whole tank rather than adding more salt on top.

No brine draw. According to the Fleck table, suction fails when the DLFC, the injector or its screen is clogged, when supply pressure sits below 20 psi, or when the valve leaks internally. On a 5600SXT, SoftPro's check is to start a cycle, step it to the BD position, pull the brine tube off at the float and see whether it sucks. If it doesn't, look at the injector, the drain line and the brine valve. The injector cleaning guide walks through taking it apart.

Too much water in the brine tank. Here the Fleck table points to clogs at the injector or DLFC, a control that has stopped stepping, or grit lodged in the brine valve.

Valve and settings problems

When salt and brine check out, look at what the valve has been told to do.

• Hardness setting. The valve wants untreated hardness in gpg; a lab report in mg/L converts by dividing by 17.1, rounded up. Iron raises the number you enter; see water softener settings.
• Regeneration frequency. A roughly weekly cycle on a lean salt setting is the target. The store guides vary between 2 and 7 days with hardness and household use, and the Penn State worked example comes out at 6 to 7 days.
• Drain runs nonstop. Fleck's table traces this to a piston that won't find its position, grit inside the control, or a leak across internal seals.
• Error codes. Code meanings differ between Fleck board versions, so read them only from the manual that matches your board. Check the part number printed on your manual's cover.
• Internal leaks. Worn seals, spacers or a worn piston let hard water slip past the resin. For the 5600SXT, Quality Water Treatment suggests a yearly rebuild of piston, seals and spacers using kit #60010307.

If a Fleck valve body is cracked or the board keeps failing, a new head may cost less than repeated repairs. Quality Water Treatment sells the Fleck 5600SXT 3/4-inch electronic meter valve (sold by Quality Water Treatment, our store) for replacing a worn head, from $469 (October 2026); the store says it replaces the older 5600SE.

Resin problems

Resin is the last thing to suspect because it fails slowly. Signs include hardness creeping back sooner after each regeneration, falling pressure, or beads at the taps.

• Iron fouling. Once iron passes 0.3 ppm, Quality Water Treatment's install guide calls for regular Pro-Res cleaning, at least twice a year with clear-water iron and sooner if treated water shows iron. A resin cleaner poured into the brine well handles this.
• Clogged resin. Penn State Extension says red, oxidized iron (iron exposed to air or chlorine) will clog the resin, and that some resin cannot be washed clean and has to be replaced.
• Bacteria and odor. If the incoming water carries bacteria or organic material, Pentair says it can foul the unit and cause off-tastes. The cure is sanitizing with unscented household bleach: Pentair lists 1.2 fl oz for each cubic foot of resin, SoftPro and QWT about 2 fl oz, so use whatever your own manual gives.
• Beads in the water. SoftPro describes resin beads as small, dark and round, about 0.3 to 1.0 mm, and names a cracked bottom distributor or damaged screens as the usual cause.

If cleaning no longer restores capacity, the resin itself may need replacing.

When to replace

Control heads are designed for service, so seals and pistons can be swapped. Repair makes sense when the tank is sound and the fault is one part: an injector, a brine valve, a bypass or a board. Replacing resin makes sense when the valve is fine but capacity has dropped and cleaning no longer helps.

Replacing the whole system is worth pricing when the resin tank is cracked, parts for an old valve are hard to find, or the household has outgrown the unit and it regenerates far more often than about once a week. If repair costs approach replacement, compare a new system: Penn State's figure for new hardware alone is about $500 to $1,500, and store pages put professional installation at $300 to $800 (SoftPro) or $300 to $1,000 (QWT). On a private well, any new softener goes after the pressure tank. Whatever you choose, keep up the routine maintenance so the next one lasts.

Common questions

Parts for this job

Fleck 5600SXT 3/4" Electronic Meter Valve for Water Softeners

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