Key Takeaways
A small alarm that took over a house
In a staff house in the Netherlands, a compact domestic water softener started beeping every few seconds and simply would not stop. What should have been a quiet background appliance turned into the loudest presence in the building.
A modern softener with a strong opinion
The device was an AquaStar 800 SHE Plus water softener: a single-column, ion-exchange system with a Dutch-language display, automatic regeneration, built-in salt detection, and a brine tank that can hold about fifteen kilograms of salt. Its controller repeatedly reported salt-related status messages while insisting there was still a fault.
When “just add salt” is no longer enough
The user opened the brine tank, checked the float, added several kilograms of granular water-softener salt, stirred the brine, topped it up with water and ran multiple regeneration cycles. The salt bed was wet and fully submerged, yet the alarm kept sounding. That behaviour pointed toward a float that no longer floated properly, or a sensor that no longer recognised it, rather than a simple shortage of salt.
A careful line between DIY and service work
After the obvious checks were exhausted, the situation was described systematically for the manufacturer’s service department: the constant beeping, the Dutch messages on the screen, the empty tank at the start, the refilling, the extra water, the repeated regenerations, and the uncooperative float. The softener was part of staff housing managed by a Dutch temporary employment agency, so opening up internal components was not the tenant’s decision to make.
A quiet lesson from a noisy machine
The episode shows how far responsible home troubleshooting can go and where it must stop. Checking salt, filling the tank, understanding the display and running a proper regeneration are all appropriate. Persisting alarms after that are usually a sign that a component fault needs expert attention, not more guesswork at the keypad.
Story & Details
The sound that would not stop
It began with a noise that did not sound serious at first: a short, sharp beep, repeated again and again somewhere in the house. It was not tied to any obvious action; there was no smoke, no open door, no kitchen timer. It was simply there, every few seconds, day and night.
The source was tracked down to a neat white unit in the utility area. It was not a boiler, not a router, not a thermostat. It was the household water softener, mounted near the incoming mains, quietly responsible for keeping limescale off pipes, taps and appliances. Quietly, except for that alarm.
Discovering the AquaStar
A closer look revealed the nameplate: AquaStar 800 SHE Plus. Product information published for this model describes an eight-litre resin bed and a yearly softened-water capacity of roughly one hundred sixty-six cubic metres, enough for a small to medium household. The brine tank under its hinged lid can hold about fifteen kilograms of salt, and the control head includes salt detection so that the machine can warn when brine is not available for regeneration.
The display used Dutch terms to describe its state. During automatic or manual regenerations it stepped through phases: one for drawing brine through the resin, one for rinsing with fresh water, one for refilling the brine tank. Another line referred to service tips and days remaining, suggesting that the system kept track of when it expected maintenance or checks.
Yet the clearest message was not on the screen. It was the alarm tone, fired off every few seconds, indicating that the softener believed something was wrong with the salt or brine.
Button-level attempts
The first attempts to calm the machine focused on the keypad. A long press on the square confirmation button brought up an installer code screen reading “000”. While that screen was shown, the beeping stopped. For a moment, the problem felt solved. But the controller soon left that mode and returned to its usual status display, and with it came the alarm again.
Other combinations were tried. Holding the up and down buttons together opened deeper configuration menus with options and service parameters. These modes also silenced the alarm while active, but once the device slipped back into its standard operating screen, the salt warning resumed. The pattern was clear: configuration states could hide the symptom, but they were not removing the underlying cause.
The logic in a softener like this does not simply count days since the last refill. Information from AquaStar and similar softeners shows that these units use both time and internal state, including brine level and salt detection, to decide when alarms are appropriate. The pad alone cannot override what the sensors report.
Opening the brine tank
With the buttons exhausted, attention turned to the hardware that the alarm was complaining about. Lifting the top cover revealed the brine section: a grey internal reservoir containing water, a residue of old salt and a vertical float assembly designed to rise with the brine level. The float could be nudged up and down by hand but did not appear to sit high in the water on its own.
Ion-exchange softeners work by passing hard water over resin beads that trade hardness ions such as calcium and magnesium for sodium. Eventually the resin fills up and needs to be rinsed with brine, a concentrated solution made by dissolving salt in the brine tank. Manufacturer documentation and independent water-treatment guides stress that this brine, and the mechanism that controls and monitors it, is essential to the entire process.
If the brine tank runs dry or the float never rises, the softener is right to complain. It cannot reliably regenerate the resin without that chemical backbone.
Refilling with salt
The simplest explanation for the alarm was also the most obvious: the system was low on salt. Looking into the tank confirmed that only a modest layer remained. A refill was unavoidable.
Dedicated water-softener salt is widely available. Hardware chains such as Gamma, for example, sell Axal salt tablets specifically intended for water softeners, highlighting their high purity and controlled dissolving behaviour in marketing material. Buying a full twenty-five-kilogram sack is the standard, economical approach when transport and storage are simple.
Here, the user needed something lighter to carry back on foot. That led to several kilogram packages of coarse granular salt sold for domestic water appliances. It was not marketed under the “softener tablet” label but was still a refined sodium chloride product intended to be dissolved in water.
About four kilograms of this granular salt were poured into the brine well. The crystals sank, absorbed water and began to lose their sharp edges as they dissolved. The float was tested again. It could be lifted manually and moved, but when released it still settled low.
Regeneration with new brine
With salt present again, the softener was told to regenerate using its standard programme. It stepped into the brining phase, pulling salty water through the resin bed, then into rinsing, then into refilling. Flow sounds in the pipes and the changing messages on the display confirmed that the sequence had run.
When the cycle finished, there was a real expectation that the alarm would stop. The tank now held fresh brine, and the resin had been treated. If the salt problem had been only a matter of quantity, the softener should have been satisfied.
Instead, the beeping resumed.
More salt was added, bringing the total mass in the tank to roughly six kilograms. While that did not approach the full fifteen-kilogram capacity of the reservoir, it was more than enough, under normal circumstances, to create a brine layer deep enough to lift a working float. The tank contents were stirred by hand to break up any crust and to help newly added salt crystals dissolve more evenly. Another regeneration followed. Afterwards, the same sound returned.
At this point, the likelihood that “not enough salt” was still the explanation dropped sharply.
Water level and the reluctant float
Attention shifted from how much salt was present to how the float behaved. It seemed to rest on the salt bed rather than gliding freely in a column of liquid. In some cases this can simply mean that there is water present but not enough of it to rise above a thick layer of salt crystals.
A cautious top-up followed: around one and a half litres of tap water were poured gently into the brine tank, taking care not to slam the float assembly. The goal was simple: ensure that every salt crystal was under water and that the float had room to rise.
After a short wait, the float was moved again by hand. It could be lifted, but when released it did not stay high. It dropped back toward the salt surface instead of settling at a clear, floating position near the top of the brine. Visually, the tank no longer looked starved of either salt or water. The alarm, however, continued.
Guidance on how softeners are meant to behave describes this as a turning point. Once the salt bed is clearly wet, the tank holds several kilograms of salt and the softener has run full regenerations, a persistent salt alarm is less likely to reflect user maintenance and more likely to indicate a problem with the float or the sensor watching it.
A float that has taken on water, become too heavy with deposits or suffered mechanical damage can lose buoyancy and simply sink in brine that used to carry it. A level sensor that has failed electrically can misread even a healthy float. In both cases the control logic sees “no brine” and sounds the same alarm.
Recognising the limits of home repair
It helped that the installation had not been anonymous. Documentation for the softener, including a guarantee note, showed that it belonged to an AquaStar line supplied and supported by Fegon Waterbehandeling B.V., a Dutch water-treatment specialist. The company’s own site emphasises that it stands alongside installers and end users with technical support, service and warranty handling.
The softener itself was part of staff accommodation owned and managed by a company rather than the person living there. That detail mattered. Replacing floats, opening sensor housings or adjusting internal wiring are not things a tenant is expected or allowed to do. Those are tasks for an installer or service technician.
The situation was therefore set out in clear, technical terms for the support team: a specific AquaStar model in staff housing, a constant salt alarm, Dutch status messages indicating normal regenerative phases, an initially low salt level now corrected with several kilograms of suitable salt, a brine tank that was unquestionably wet and a float that would move under a hand but not float independently. The account made it clear that the user had avoided forcing settings, had not opened sealed components and had stopped short of anything that could compromise safety or warranty.
From there, the next step lay with the manufacturer and its partners. A technician might confirm a heavy float and replace it, clean or swap a level sensor, or discover an entirely different internal issue. Whatever the cause, the path ran through the people who routinely open these units and are insured and trained to do so.
In the meantime, the story of the beeping softener had reached a natural pause. All the reasonable user-level actions had been taken. The alarm had done its job: it had refused to let the system quietly coast along in a half-working state.
Conclusions
What the alarm was really saying
The AquaStar’s alarm did more than complain about discomfort. It protected the regeneration process for the resin bed. Without enough properly detected brine, a softener like this cannot guarantee that hardness minerals are stripped out of the water. Persistent beeping, in that light, is not a nuisance but a refusal to pretend that everything is fine.
When persistence stops being persistence and becomes carelessness
There is a line between persistence and denial. In this case, that line ran through the brine tank. Once the softener had been given several kilograms of appropriate salt, enough water to submerge it, repeated regenerations and gentle checks on the float, the likelihood of a simple user error shrank. Continuing to treat the fault as “probably just a bit more salt” would not have been determined; it would have been careless.
Recognising the limits of what can be done from the outside of the casing allowed the situation to be handed over to people with the right tools and authority to open the unit. That decision protected the equipment, the building and the person living there.
A quiet outcome, eventually
The beeping water softener turned into an unexpected technical lesson on how ion-exchange units work and how they signal trouble. It also offered a calmer, more practical insight: not every alarm is meant to be defeated. Some are designed to be answered, even if the answer is a phone call to someone with a toolbox.
In a well-run home or staff house, that is exactly how it should be.
Sources
AquaStar 800 SHE Plus product page, including resin volume, yearly capacity, salt reservoir size and salt detection.
https://aquastar-waterontharder.nl/producten/aquastar-800-she-plus/
Overview of AquaStar water softeners and their principle of removing hardness through ion exchange using salt for regeneration.
https://onlinewaterontharders.nl/c/aquastar/
Information on Fegon Waterbehandeling B.V. as the supplier and service partner for AquaStar systems.
https://fegon-waterbehandeling.nl/aquastar-waterontharder/
Product description for Axal salt tablets for water softeners sold via a major Dutch hardware chain.
https://www.gamma.nl/assortiment/axal-zouttabletten-voor-waterontharder-25-kg/p/B277436
Guidance from the U.S. Department of Energy on how salt-based water softeners work in the home.
https://www.energy.gov/energysaver/purchasing-and-maintaining-water-softener
Educational article from the University of Minnesota Water Resources Center on household water softening and hardness.
https://wrc.umn.edu/watersoftening
Extension publication on ion-exchange softening, resin behaviour and sodium chloride use in domestic systems.
https://www.wellwater.bse.vt.edu/files/442-664%28BSE-258P%29.pdf
Training announcement from the American Society of Plumbing Engineers linking to an instructional softener video by Water Control Corporation.
https://aspe.org/pipeline/wcc-releases-new-training-video-how-does-a-water-softener-work/
Water Control Corporation’s educational video “How Does a Water Softener Work?” on YouTube.
https://www.youtube.com/watch?v=FmnvcaxXtto
Appendix
AquaStar 800 SHE Plus
A compact domestic water softener produced under the AquaStar brand, built around an eight-litre ion-exchange resin bed. It is specified for a yearly softened-water capacity of roughly one hundred sixty-six cubic metres, includes automatic regeneration and salt detection, and has a brine tank sized for about fifteen kilograms of salt.
Brine tank
The section of a water softener that holds solid salt and water together so that a concentrated salt solution can form. During regeneration, the softener draws this brine into the resin column to flush out accumulated hardness ions and restore the resin’s ability to soften water.
Dishwasher salt
A coarse, high-purity sodium chloride product marketed for dishwashers that include a built-in softening unit. Although it is not optimised for large brine tanks and is sold in smaller packages, it is chemically similar to dedicated water-softener salt and can sometimes be used as a temporary source of brine.
Float
A buoyant component mounted in the brine tank, designed to rise and fall with the level of brine. In many designs it also serves as a safety element to prevent overfilling and works with sensors or mechanical linkages to inform the control unit about the availability of brine for regeneration.
Ion-exchange water softener
A system that removes hardness minerals such as calcium and magnesium from water by passing it through a bed of resin beads. These beads hold sodium ions and exchange them for hardness ions in the water. When the resin becomes saturated, it must be regenerated using brine so that the exchange process can continue.
Regeneration cycle
The sequence of steps a softener uses to restore its resin bed after it has captured hardness minerals. This typically involves drawing brine through the resin, rinsing with fresh water to clear out salt and displaced minerals, and refilling the brine tank so that new brine can be created for the next cycle.
Salt alarm
An audible and visual signal generated by the softener’s control system when it determines that there is not enough usable brine to carry out a proper regeneration. In systems with level detection it is usually linked to the position or behaviour of a float and any sensors that monitor it, rather than to a simple time-based schedule.
Water-softener salt
Salt formulated and packaged specifically for use in water-softener brine tanks, often in the form of tablets or coarse crystals. It is produced with high purity and controlled dissolving behaviour to reduce the risk of sludge, bridging or blockages while maintaining a stable supply of brine for the regeneration process.
My Diary - Leonardo Cardillo 