Why does my water softener keep draining or run to drain continuously?

Continuous drain flow means the control valve is stuck in a regeneration position rather than returning to service. The usual causes are a failed valve motor stopping mid-cycle, a stripped or worn drive gear or cam, a failed timer board, or debris holding a piston or seal stack off its seat. On a commercial system this wastes both water and softening capacity continuously, and it can run a meter bill up quickly, so bypass the unit immediately to stop the loss while you diagnose. Try a manual regeneration first: if the valve advances normally through each stage under manual command, the fault is in the timer or initiation circuit rather than the drive. If it does not advance, the motor, gear, or seal stack needs service.

What is a salt bridge and how do you fix it?

A salt bridge is a hardened crust of salt spanning the brine tank with a hollow void underneath. The salt above looks normal and the tank may appear full, but the water below never contacts the salt, so no brine forms and every regeneration cycle rinses the resin with plain water. Diagnose by probing straight down through the salt with a broom handle or dowel: if the probe suddenly drops through a cavity, the bridge is confirmed. Break it up by working the probe around the full circumference, taking care not to strike the float assembly or the brine pickup at the tank bottom. Then run a manual regeneration and verify hardness 24 to 48 hours later. Prevent recurrence by keeping the tank no more than two-thirds full, using solar or crystal salt instead of pellets in humid rooms, and keeping regeneration frequency at least every three to four days.

How do I know if my softener resin is bad?

Resin failure is a diagnosis of exclusion — rule out bypass position, salt level, salt bridge, injector clog, and float valve first, because all of those are far more common and far cheaper. Genuine resin failure shows as reduced capacity that does not respond to a correct regeneration with confirmed brine draw. Pull a resin sample: healthy resin is uniform amber to dark gold, hydrated, and free-flowing. Orange or rust-colored beads indicate iron fouling. Beads that are broken, flattened, or mushy indicate chlorine attack or osmotic shock. Iron-fouled resin can often be recovered with a chelating resin cleaner run through several regeneration cycles. Properly maintained resin lasts 10 to 20 years; failure inside five years almost always means iron fouling, chlorine degradation, or turbidity clogging rather than normal wear.

Should a water softener go before or after a filter?

Sediment and iron filtration go before the softener; carbon placement depends on what you are protecting. A sediment prefilter upstream protects the resin bed from physical clogging by turbidity, and any oxidized ferric iron must be removed upstream because it plugs resin rather than exchanging onto it. On chlorinated municipal supplies, carbon ahead of the softener protects the resin from oxidative degradation, which is a leading cause of premature resin failure. The exception is where carbon media itself would shed fines into the resin bed, in which case a sediment filter belongs between them. Reverse osmosis always goes last, downstream of softening, because soft feedwater is what protects the RO membrane from calcium scaling.

Why is my water softener making a loud noise?

Noise during regeneration is usually normal — brine draw and backwash both move water at high velocity and produce audible flow. Diagnostic noises are the ones that are new, continuous, or occur during service rather than regeneration. A grinding or clicking from the valve head points to a worn drive gear or cam. A continuous hum with no cycle advance points to a stalled motor. Banging or hammering on cycle transitions is water hammer from fast-closing valve positions, often worse where the system was installed without arrestors on a rigid pipe run. High-pitched whistling during brine draw usually means a partially obstructed injector. On commercial systems, a rhythmic surging during service can indicate resin bed channeling from inadequate backwash flow.

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Home › Guides › Water Softener Troubleshooting

Water Softener Troubleshooting: A Commercial Diagnostic Guide

Q: Why is my water softener not making soft water?

Work the checks in order of likelihood and cost. First confirm the bypass valve is in service position, not bypass — this is the single most common cause after maintenance work. Second, check the brine tank for salt level and probe for a salt bridge, a hardened crust that leaves a hollow cavity so no brine forms even though the tank looks full. Third, verify brine is actually being drawn during regeneration by marking the brine tank water level before a cycle and checking it after; if the level has not dropped, the brine injector is clogged or the float valve is stuck. Fourth, test raw and treated hardness with a titration kit to confirm the softener is actually the problem and that source hardness has not increased. Only then suspect exhausted or fouled resin, which is the most expensive diagnosis and the least common.

Q: Why is my brine tank full of water?

A brine tank holding more water than normal, or overflowing, points to one of four faults. The brine float valve may be stuck open so refill never shuts off. The brine injector may be clogged so no brine is drawn during the cycle, leaving behind the water that was added at the previous refill. The drain line may be restricted or kinked, preventing the cycle from completing. Or the control valve may have failed to advance out of the refill position. Diagnose by checking whether the level drops during a manual regeneration: if the level never falls, the fault is on the draw side — injector or float. If it falls but refills excessively, the fault is the float valve or the refill timing setting.

Reviewed by Lawrence Quarles, Alabama Grade IV Wastewater Treatment Operator · Updated August 2026

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Softener failures are mechanically identical whether the unit serves a house or a hotel — a bridged brine tank, a plugged injector, and a stuck float behave the same way at any scale. What differs commercially is that hard water reaching a dish machine, boiler, or RO train has a cost per hour, the sizing math runs on peak flow rather than occupants, and a single-tank system leaves you with no soft water at all during regeneration. This guide works symptom-first, in the order a service technician would actually check things: cheapest and most likely causes before expensive ones.

Before anything else, the ninety-second check. Confirm the bypass valve is in service, not bypass. Then confirm there is salt in the brine tank and that a probe reaches solid salt at the bottom. A large share of "the softener failed" calls end here, and both checks are free. If either one is the answer, correct it, run a manual regeneration, and retest hardness in 24 to 48 hours before pursuing anything further.

What failure actually costs
The regeneration cycle
The diagnostic sequence
Hard water returning
Softener not regenerating
Running to drain continuously
Brine tank full of water
Salt bridges and mushing
The brine injector
Leaks and noise
Resin fouling and failure
Commercial sizing math
Softener placement in the train
Preventive maintenance schedule
FAQ

What failure actually costs

The reason commercial troubleshooting differs from residential isn't technical — it's that the clock is running. Hard water bleeding past a failed softener does measurable damage downstream, and in several applications it stops the operation entirely.

Application	What hard water does	Time to consequence
Reverse osmosis feed	Calcium carbonate scaling on the membrane surface; permanent flux loss and rejection decline	Hours to days. The most expensive failure on this list — membranes are not recoverable once heavily scaled.
Steam boiler feedwater	Scale on heat transfer surfaces; efficiency loss, tube overheating, potential tube failure	Days. Scale is an insulator; a thin layer measurably raises fuel consumption.
Commercial dish machines	Spotting and filming on ware, scale on the booster heater and wash arms, detergent demand rises	Immediate visible effect on ware; scale accumulates over weeks.
Cooling towers	Scale on fill and condenser tubes; approach temperature rises, chiller efficiency drops	Weeks. Interacts with cycles of concentration — hardness in makeup compounds fast.
Espresso and beverage	Scale in boilers and group heads; taste change is immediate and noticeable to customers	Immediate taste impact; equipment damage over weeks.
Laundry (hospitality, healthcare)	Detergent efficiency falls sharply, linens gray and stiffen, rewash rates rise	Immediate. Linen replacement cost is the hidden line item.
Scale impact data on heat transfer equipment from Battelle Memorial Institute research commissioned by the Water Quality Research Foundation, which measured up to 48% water heater efficiency loss on hard water and tankless failures inside 1.6 years.

The single-tank problem. A simplex (single-tank) softener produces no soft water while it regenerates — typically 60 to 120 minutes. Residentially that's tolerable because it runs at 2 AM. In a 24-hour operation, a hotel with early check-outs, or a facility feeding an RO train continuously, that window is a genuine hardness breakthrough. If your operation cannot tolerate it, the correct configuration is twin-alternating (duplex): two tanks where one stays in service while the other regenerates, giving uninterrupted soft water. If you are diagnosing intermittent hardness complaints that correlate with time of day, check the regeneration schedule before suspecting a fault — the system may be working exactly as designed and simply be the wrong configuration for the duty.

The regeneration cycle

Every fault below is a failure of one specific stage, so diagnosis is much faster if you know what each stage is supposed to do. Softening itself is straightforward: sulfonated polystyrene resin beads carry a negative charge and hold sodium ions loosely. Calcium and magnesium carry a double positive charge, bind more strongly, and displace the sodium as water passes through. When every exchange site is occupied, the bed is exhausted and must be regenerated.

Stage	Flow direction	Purpose	Typical duration
1. Backwash	Upflow — reverse of service	Lifts and fluidizes the resin bed, expanding it by roughly 50%, releasing accumulated sediment and iron to drain and breaking up compaction and channeling	8–12 min
2. Brine draw / slow rinse	Downflow (co-current) or upflow (counter-current)	Draws 8–12% brine through the bed. High sodium concentration reverses the exchange, stripping calcium and magnesium off the resin to drain. The stage where most faults hide.	30–60 min
3. Fast rinse	Downflow, service rate	Flushes residual brine and displaced hardness, resettles the bed after backwash expansion	8–15 min
4. Brine refill	Into brine tank	Refills the brine tank to a preset level so salt dissolves for the next cycle	6–12 min
Backwash is upflow. Service flow in a conventional downflow softener runs top to bottom; backwash reverses it bottom to top to lift the bed. Sources describing backwash as "downward in reverse" have it wrong, and the distinction matters — inadequate backwash flow means the bed never expands, which causes the channeling that produces hardness leakage with no other obvious fault.

Water consumption is roughly 50 gallons per regeneration on a residential-scale unit and scales with tank size from there. On septic systems this discharge is a hydraulic loading concern; on commercial systems with brine discharge limits it may be a permit concern.

The diagnostic sequence

Work these in order. The sequence is deliberately arranged cheapest-and-most-likely first, because the expensive diagnosis — resin replacement — is also the rarest, and technicians who start there replace a lot of perfectly good resin.

Bypass valve position. Service or bypass? After any plumbing work, filter change, or contractor visit, this is the first suspect. Free to check, instant to fix.
Salt level and salt bridge. Is there salt? Does a probe reach solid salt at the bottom, or does it drop through a void? A bridged tank looks full and produces no brine.
Confirm brine draw. Mark the brine tank water level, run a manual regeneration, check the level afterward. No drop means no brine was drawn — the cycle rinsed the resin with plain water. This one test separates brine-side faults from resin faults and is the most useful single check in this guide.
Test raw and treated hardness. Titration kit on both the inlet and outlet. Confirms the softener is actually the problem, and catches the case where source hardness has risen and the unit is simply undersized now.
Check the control valve cycles. Run a manual regeneration and watch it advance through all four positions. Does it move? Does it stall? Does drain flow start and stop when it should?
Inspect the injector and float. If brine isn't drawing and the tank isn't bridged, pull the injector and inspect the orifice, and check the float assembly for debris or sticking.
Sample the resin. Only now. Color, texture, and bead integrity tell you whether fouling or degradation has occurred.

Hard water returning

Symptom: scale, spotting, or soap scum returns after the softener was working

Check first: bypass valve position, then salt level and bridge, then confirm brine draw with the level-mark test.

Likely causes, in order: bypass valve open · salt depleted · salt bridge preventing brine formation · brine injector clogged so no brine is drawn · float valve stuck closed so the tank never refills · control valve not initiating regeneration · source hardness increased · resin fouled or exhausted.

The undersizing case. If hardness returns predictably before the next scheduled regeneration rather than randomly, the system is running out of capacity rather than failing. That points to increased demand, increased source hardness, or iron consuming capacity — see the sizing section. On well supplies especially, hardness is not constant, and a softener sized correctly three years ago may not be sized correctly now.

The channeling case. Persistent low-level hardness leakage with normal brine draw and healthy resin usually means channeling — water carving preferential paths through a compacted bed instead of contacting all the media. The cause is inadequate backwash flow rate. Verify backwash flow against the manufacturer's specification for the tank diameter; too low and the bed never fluidizes.

Softener not regenerating

Symptom: no cycle occurs, or the cycle runs but water stays hard

Check first: power and programming, then initiate a manual regeneration and watch what happens.

No cycle at all: unit unplugged or on a dead circuit · programming lost after a power interruption (display reset to 12:00 is the tell) · failed valve motor · stripped drive gear or cam · failed timer board · on metered systems, a fouled flow-meter turbine that never registers volume, so the regeneration trigger never fires.

Cycle runs but water stays hard: this is nearly always a brine-side fault, not a valve fault. Salt bridge · clogged injector · stuck float valve · brine line air leak breaking the siphon mid-draw. Run the level-mark test.

Metered systems specifically. A turbine that has fouled with iron or debris stops counting, so the controller believes no water has been used and never initiates. Symptom is a capacity-based system that has not regenerated in an implausibly long time. The turbine is usually accessible at the valve outlet and cleans easily.

After any power outage, verify both the time of day and the regeneration schedule. A controller that reset will regenerate at the wrong hour — which in a commercial building can mean a hardness breakthrough during peak service on a simplex system.

Running to drain continuously

Symptom: water runs to drain constantly; softener never returns to service

Do this first: put the unit in bypass to stop the water loss, then diagnose. On a commercial meter this fault is expensive by the hour and it will not fix itself.

Cause: the control valve is stuck in a regeneration position rather than returning to service. Specifically — motor failed mid-cycle · drive gear or cam stripped or worn · timer board failure · debris holding a piston or seal stack off its seat · a seal stack worn enough that the drain port never fully closes.

Narrowing it down: command a manual regeneration. If the valve advances normally through each position under manual command, the drive train is intact and the fault is in initiation or the timer. If it will not advance, the fault is the motor, gear, or seal stack.

The partial version of this fault is a slow continuous trickle to drain rather than full flow, and it is easy to miss for months. It usually means a worn seal stack or a piece of resin lodged on a seat. Check the drain line for flow while the unit is in service — there should be none at all.

Brine tank full of water

Symptom: brine tank holding excessive water, or overflowing

Diagnostic: mark the level, run a manual regeneration, observe. Does the level fall during brine draw?

Level never falls → the draw side has failed. Clogged injector (most common) · brine line obstruction · air check valve failure breaking the siphon · brine pickup screen fouled. The water you are seeing is simply last cycle's refill that was never consumed.

Level falls then overfills → the refill side has failed. Float valve stuck open · float set too high · refill timing set too long in the controller.

Level rises during service → a check valve failure allowing water to flow backward into the brine tank between cycles.

Also check the drain line. A kinked, frozen, or restricted drain line, or one run too high above the valve, prevents the cycle from completing and can back water into the brine tank. Drain lines need an air gap and should not be elevated beyond the manufacturer's stated lift limit.

Salt bridges and mushing

A salt bridge is a hardened crust spanning the tank with a void beneath it. The salt above looks normal — the tank may even look full — but the water below never touches it, so no brine forms and every regeneration rinses the resin with plain water. It is the most common preventable softener failure and the most frequently misdiagnosed, because the tank passes a visual inspection.

Diagnosing and clearing

Probe straight down through the center of the salt with a broom handle or wooden dowel, using moderate force.
If the probe suddenly drops through a cavity, the bridge is confirmed.
Break it up by working the probe around the full circumference. Avoid striking the float assembly or the brine pickup tube at the tank bottom — damaging either turns a free fix into a parts order.
Let the broken salt fall. Add water manually if the level is very low, or let the refill cycle handle it.
Run a manual regeneration to draw fresh brine through the resin.
Test hardness 24 to 48 hours later to confirm capacity is restored.

Cause	Mechanism	Prevention
High humidity	Moisture condenses on the salt surface and bonds adjacent pellets	Site the brine tank in a dry, conditioned space; avoid mechanical rooms with steam or open floor drains
Pellet salt in humid rooms	Binder-formed pellets bridge more readily than coarse salt	Switch to solar or crystal salt in humid installations
Overfilling	Salt compressed against itself for long periods bonds into a crust	Never fill beyond two-thirds. Smaller, more frequent additions beat topping off — this is the single most effective prevention and the most commonly ignored
Infrequent regeneration	Undisturbed salt cakes over time	Regenerate at least every 3–4 days; program seasonal or low-occupancy facilities accordingly rather than leaving them idle

Salt mushing is the related failure: salt dissolves and recrystallizes into a dense sludge at the tank bottom, plugging the brine pickup. Symptoms overlap with bridging but the fix differs — the tank must be emptied, the sludge scooped out, the tank washed, and the brine line flushed. Mushing is usually a salt purity problem; switch to a higher-grade salt after cleaning.

The brine injector

The injector — also called the venturi, eductor, or aspirator — is a small fitting inside the valve body that creates the suction drawing brine from the tank. Water accelerating through a constriction produces a pressure drop that pulls brine in from the side. The orifice is small, and when it plugs with sediment, iron, or scale, no suction is created and no brine is drawn.

This is the most-missed diagnosis in softener troubleshooting. The system appears to work perfectly — the valve cycles through every stage on schedule, drain flow starts and stops correctly, the display shows a completed regeneration. But no salt was drawn, so the resin was never regenerated. Nothing about the observable behavior indicates a fault. The only way to catch it is the brine tank level test: mark the level, regenerate, check whether it dropped.

Symptom	Cause	Service action
Brine level unchanged after regeneration	Injector orifice fully blocked	Remove injector cap and nozzle, clear the orifice with a fine wire or needle, soak in white vinegar 30 minutes to dissolve scale, reinstall, verify with a manual cycle
Level drops partially	Partial obstruction, or a fouled injector screen	Same cleaning; if unresolved, replace the injector assembly — an inexpensive, make-and-model-specific part
High-pitched whistle during brine draw	Partial obstruction changing flow characteristics	Clean or replace injector
Water flows backward into brine tank in service	Check valve failure, or injector screen backpressure	Inspect and replace the brine line check valve; clean the screen
Injectors are sized to the tank and flow rate. When replacing, match the manufacturer's part number exactly — an injector of the wrong size draws brine at the wrong rate and degrades regeneration efficiency even though it fits.

Leaks and noise

Leaks

Locate the leak precisely before ordering anything — the fix ranges from a $10 O-ring to tank replacement.

Leak location	Cause	Fix
Around the valve-to-tank joint	Tank O-ring failure — the most common leak by a wide margin	Serviceable part. Depressurize, bypass, remove the valve head, replace the O-ring, lubricate with silicone grease rated for potable water
From the valve body itself	Internal seal stack or piston seal wear	Seal kits available for all major valve brands; on high-hour commercial valves, consider a full valve rebuild
At the brine line fitting	Loose nut, failed ferrule, or cracked tubing	Tighten carefully — these are usually plastic compression fittings and over-tightening cracks them. Replace tubing if cracked
At the bypass valve	Bypass O-rings dried out from never being cycled	Replace O-rings; exercise the bypass twice a year to prevent recurrence
From the tank body	Cracked pressure vessel — usually freeze damage or age	Tank replacement. Not repairable. Check for freeze exposure in unheated mechanical spaces

Noise

Regeneration is audibly active by design — brine draw and backwash move water fast. Diagnostic noises are the ones that are new, continuous, or occur during service rather than regeneration.

Grinding or clicking at the valve head — worn drive gear or cam. Service before it strips completely and strands the valve mid-cycle.
Continuous hum with no advance — stalled motor drawing current without turning.
Banging on cycle transitions — water hammer from fast valve closure. Common on rigid pipe runs without arrestors; add arrestors rather than trying to slow the valve.
Whistling during brine draw — partially obstructed injector.
Rhythmic surging during service — often bed channeling from inadequate backwash. Verify backwash flow rate.

Resin fouling and failure

Resin should last 10 to 20 years. Failure inside five years is almost always a preventable upstream problem rather than wear — and replacing resin without correcting that upstream cause simply restarts the clock on the same failure.

Iron: the distinction that matters

Iron form	Appearance	Softener removes it?	Required treatment
Ferrous (clear-water)	Dissolved and invisible; water is clear at the tap but rusts on standing	Yes — exchanges onto resin like hardness	None required, but it consumes capacity and must be counted in sizing
Ferric (red-water)	Visible orange or brown particles immediately at the tap	No — physically plugs the bed	Oxidation and filtration upstream — catalytic media such as Katalox Light is the usual approach. Never route ferric iron into resin
Colloidal	Faint tint or haze; no visible particles	Poorly — too fine to filter, too large to exchange	Oxidizing filter (Greensand Plus, Birm, or air injection) plus sediment filtration
Iron bacteria	Orange-brown slime; often accompanied by odor	No — colonizes and clogs the bed	Well disinfection, biological control, and resin disinfection. See the iron in well water guide

Reading a resin sample

Healthy: uniform amber to dark gold, hydrated, free-flowing, beads intact and spherical.
Iron-fouled: orange or rust-stained beads. Often recoverable with a chelating resin cleaner run through several regeneration cycles — add to the brine tank per label, regenerate immediately, repeat after two to three days for severe fouling.
Chlorine-degraded: beads soft, mushy, or fractured, and the bed volume may have visibly dropped. Not recoverable. Free chlorine attacks the divinylbenzene crosslinks that give the bead its structure. Carbon ahead of the softener is the primary defense, but the resin specification matters too: standard softener resin is 8% crosslinked, while higher-crosslink grades such as 10% crosslinked resin resist oxidative attack better and last longer on chlorinated supplies. If you are rebedding a softener that failed early on municipal water, specify the higher crosslink rather than replacing like for like.
Osmotic shock damage: cracked or shattered beads from repeated rapid concentration swings. Not recoverable.
Organic or bacterial fouling: musty odor, slimy texture. Treat with a bleach disinfection cycle — confirm compatibility with your valve and resin first, as some manufacturers prohibit it.

Before replacing resin, fix what killed it. Ferric iron reaching the bed, free chlorine with no carbon ahead of it, or turbidity with no sediment prefilter will destroy new resin on the same timeline as the old. Replacement is genuinely cheaper than a whole new system — but only once, and only if the upstream cause is corrected first. When you do rebed, match the resin grade to the water: higher crosslinking for chlorinated supplies, and correct the iron or turbidity path first if that was the cause.

Commercial sizing math

Commercial sizing differs from residential in that two independent constraints must both be satisfied: grain capacity between regenerations, and peak flow rate through the vessel. A system correct on one and wrong on the other will fail, and the failure modes look different.

Grains per day = Daily gallons × Compensated hardness (gpg)

Compensated hardness = Hardness (gpg) + (Iron mg/L × 4) + (Manganese mg/L × 2)

Days between regenerations = Capacity (grains) ÷ Grains per day

The iron correction is the one people skip. Every 1 mg/L of ferrous iron adds roughly 4 gpg of equivalent load on the resin. Water at 12 gpg hardness with 1.5 mg/L iron is not a 12 gpg problem — it is 18 gpg of compensated load, and a softener sized for 12 will run out of capacity 33% early. That symptom presents as "hard water returning before the next regeneration," which is easy to misread as a fault.

Constraint	What it governs	Failure symptom if wrong
Grain capacity	How much hardness the bed removes between regenerations	Hardness returns predictably before the scheduled cycle
Service flow rate	GPM the vessel handles while maintaining contact time	Hardness leakage only during peak demand; excessive pressure drop
Backwash flow rate	Whether the bed actually fluidizes and expands ~50%	Channeling, gradual capacity loss, resin fouling that keeps recurring
Regeneration frequency	Salt and water consumption; bed hygiene	More often than every 3 days wastes salt; longer than 7 days risks biological growth in the bed

Target regeneration every 3 to 7 days. Salt efficiency is the commercial operating-cost lever: higher salt dose per cycle buys more capacity per cubic foot of resin but at falling efficiency in grains removed per pound of salt. For high-volume facilities that difference is a real annual number, which is why counter-current (upflow) brining is common on commercial equipment — it uses brine more efficiently than co-current.

For full sizing methodology, vessel selection, and duplex configuration, see the commercial water softeners guide. To convert between hardness units, use the water hardness calculator.

Softener placement in the train

"Before or after the filter" is one of the most common questions and the answer depends on which filter and what you are protecting.

Component	Position	Reason
Sediment prefilter	Before softener	Turbidity physically clogs the resin bed. A 20–50 micron prefilter is cheap insurance
Iron / manganese oxidizing filter	Before softener	Ferric iron plugs resin rather than exchanging. Must be removed upstream
Carbon (on chlorinated supply)	Before softener	Free chlorine degrades resin crosslinking — a leading cause of premature failure. Carbon first protects the investment
Carbon (where media sheds fines)	Before, with sediment filter between	Carbon fines can foul the resin bed; separate them
Reverse osmosis	After softener	Soft feedwater is what protects the membrane from calcium scaling. This order is not optional. See RO pre-treatment
UV disinfection	After softener, last	UV needs clarity; scale on the quartz sleeve blocks transmission. Hardness above 7 gpg fouls sleeves

Softeners and drinking water. A softener exchanges hardness for sodium at roughly 8 mg/L of sodium per grain of hardness removed. On very hard water that is a meaningful sodium contribution, which matters for facilities serving sodium-restricted populations — healthcare, assisted living, schools. The usual answer is a separate unsoftened or RO-treated line for drinking and cooking. Note also that a softener does not address bacteria, nitrate, arsenic, lead, or most regulated contaminants; it is a scale-control device, not a treatment barrier.

Preventive maintenance schedule

Task	Frequency	Detail
Test treated hardness	Weekly (commercial)	The single most valuable habit. Titration kit on the softener outlet, logged. Any upward trend is early warning weeks before a complaint
Check salt level and probe for bridge	Weekly to monthly by consumption	Refill below one-third; never above two-thirds; probe while you are there
Verify brine draw	Quarterly	Mark level, regenerate, confirm drop. Catches the injector fault nothing else detects
Exercise bypass valve	Every 6 months	Full open and close. A seized bypass during an emergency is a much bigger problem than a stiff one during PM
Clean brine injector and screen	Annually, or on any draw fault	Vinegar soak and fine wire on the orifice
Clean brine tank	Annually	Empty, remove sludge, wash, rinse, inspect float and pickup
Resin cleaner (iron-bearing water)	Every 3–4 months	Chelating resin cleaner to the brine tank, manual regeneration immediately after
Verify regeneration schedule	After every power event; annually	Time of day and frequency. On simplex systems, confirm the window still falls outside peak demand
Replace sediment prefilter	1–3 months by turbidity	A clogged prefilter reads as softener pressure loss and gets misdiagnosed constantly
Inspect connections and drain line	Annually	Slow seeps leave mineral tracks. Confirm the air gap is intact

Keep a log. Date, raw hardness, treated hardness, salt added, regeneration count, and anything unusual. Trend data turns a vague "the water seems off" complaint into a diagnosis in minutes, and it is what tells you whether a repair actually worked. In regulated facilities it is also the documentation that shows the treatment system was under control.

FAQ

Why is my water softener not making soft water?

In order: bypass valve left in bypass, no salt, salt bridge, clogged brine injector, stuck float valve, no regeneration occurring, increased source hardness, fouled resin. Run the diagnostic sequence above rather than guessing — the level-mark brine draw test separates the cheap causes from the expensive one in a single regeneration cycle.

Why does my water softener keep draining?

The control valve is stuck in a regeneration position. Bypass the unit immediately to stop the water loss, then command a manual regeneration: if the valve advances normally, the fault is the timer or initiation circuit; if it will not advance, the motor, drive gear, or seal stack needs service.

Why is my brine tank full of water?

Either brine is not being drawn (clogged injector, blocked brine line, failed air check) or the refill is not shutting off (stuck float, refill time set too long). Mark the level and run a regeneration — if it never drops, the fault is on the draw side.

How do I know if the resin is bad?

Only after ruling out everything else. Pull a sample: healthy resin is uniform amber and free-flowing. Orange means iron fouling, usually recoverable with a chelating cleaner. Mushy or fractured beads mean chlorine attack or osmotic shock, which is not recoverable. Failure inside five years indicates an upstream cause that must be corrected before new resin goes in.

Should the softener go before or after the filter?

Sediment and iron filtration first, carbon first on chlorinated supplies to protect the resin, softener next, RO last. Soft water protects RO membranes from scaling, so that order is fixed.

How often should a commercial softener regenerate?

Every 3 to 7 days. More frequently wastes salt and water; less frequently allows biological growth in an idle bed. If yours falls outside that range, the system is sized wrong for current demand or the controller settings no longer match actual use.

Can I run a commercial operation on a single-tank softener?

Only if you can tolerate 60 to 120 minutes with no soft water during regeneration. Facilities running continuously, or feeding an RO train or boiler, should specify twin-alternating so one tank is always in service. If you are chasing intermittent hardness complaints that track with time of day, this configuration question is the first thing to check.

Does a softener remove iron?

Dissolved ferrous iron, yes — but it consumes capacity, roughly 4 gpg equivalent per mg/L, which must be included in sizing. Oxidized ferric iron, no; it plugs the bed and requires upstream oxidation and filtration. Sending ferric iron into a softener is one of the fastest ways to destroy a resin bed.

Related Guides

Well Water Test Kits — What to Test For and What Can't Be Mailed
Sulfur Smell in Water — hydrogen sulfide diagnosis, SRB testing, and treatment by concentration
Commercial Water Softeners — Technology, Sizing, and Maintenance
Hard Water: What It Is, How to Test It, How to Treat It
Water Hardness Calculator — GPG, PPM, mg/L Conversions
Iron in Well Water — Ferrous vs. Ferric and Treatment by Type
Commercial RO Pre-Treatment Guide
Measuring TDS in Water — What Your Meter Actually Measures
Chloramine in Water — Why Carbon Placement Matters
Water Treatment for Restaurants and Food Service

Sources: Penn State Extension, "Water Softening," extension.psu.edu (Robillard, Sharpe & Swistock; updated September 2025) — hardness classification, ion exchange chemistry, resin fouling and maintenance, regeneration water use, sizing methodology, sodium contribution. · Battelle Memorial Institute research commissioned by the Water Quality Research Foundation — hard water impact on water heater efficiency and appliance service life. · Water Quality Association technical references. · Standard ion exchange practice for backwash bed expansion and brine concentration. Regeneration stage flow directions verified against control valve engineering references. This guide is informational and does not constitute engineering advice; verify all procedures against your specific equipment manufacturer's documentation before service.