When a water softener in a St. Louis home stops doing its job, the usual signs are familiar: spots on dishes, a scale ring in the tub, skin that feels dry after a shower, or soap that does not lather well. Before you add salt, change a setting, or call for service, run a few simple checks. Many softener complaints come from the brine tank, the bypass valve, or a hardness reading taken at the wrong spot, not from a failed unit.

Start with a hardness test at the right spot

Hardness is measured in the water itself, so where you sample matters. Test water from a cold tap that sits after the softener, and if you can, compare it with a cold tap that draws water before the softener. That tells you what the unit receives and what it delivers. Use a home test kit with clear instructions, rinse the container, and write down the result with the date. Compare two or three readings over a week before deciding the unit has failed. Hardness can shift with the source, and a single reading can mislead you.

Check the brine tank before anything else

The brine tank is the most common cause of a softener that seems to have quit. Open the lid and look:

  • Is there salt in the tank at all? A low tank cannot regenerate the resin properly.
  • Is there a hard crust or bridge, where salt has formed a dome over an empty space underneath? Break it up with a wooden stick or broom handle, not a metal tool that could damage the tank.
  • Is the salt mushy or sludgy at the bottom? That often means the salt has picked up debris or has stayed wet too long, and the tank may need cleaning.
  • Is there a film of oil, rust-colored sediment, or an odd smell? Note these, because they point to a different problem than salt alone.

Confirm the bypass valve is in service

A softener with its bypass valve partly or fully open sends hard water straight into the house. This often happens after maintenance, after plumbing work on the line, or when someone turns the handles to troubleshoot and forgets to turn them back. Look at the valve handles on the supply and bypass lines. The unit should be in normal service position with the bypass closed. If you are unsure which position is correct, take a photo before you change anything so you can return it to where it was.

Look at the control settings

Many softeners regenerate on a timer, and a schedule that does not match your household can leave the resin exhausted between cycles. Check the display for the correct time, since a power interruption can reset it. Confirm whether the unit regenerates by days or by water use, and check that the setting still fits how your home uses water. If you recently moved, changed a water heater, or added a bathroom, the setting may no longer match the house. Change one setting at a time and retest after several days, so you know which change helped.

Watch for signs of resin fouling

Resin can become coated with iron, sediment, or oils over time. If your water carries iron, the resin may need a cleaner made for that job, because a salt-only routine will not fully fix it. Warning signs include orange staining on fixtures, a metallic or rotten egg taste from the hot side, and hardness readings that drop after regeneration then climb again quickly. If you want to compare your readings with the source water, look for the annual water quality report published by your St. Louis area water provider. Keep in mind that these reports describe water at the treatment plant or in the distribution system, not what happens inside your home plumbing.

Keep a short log

Write down the date, the hardness reading, the salt level, the current setting, and anything you changed. A few weeks of notes will show patterns. A softener that fails every few days points in one direction, while a slow decline over a season points in another. If you call a service person later, the log gives them something concrete to work from.

When to stop troubleshooting

If the brine tank is full, the bypass is in service, the settings are correct, and the hardness readings still show hard water, the problem may be internal, such as a control valve that does not advance or a resin bed that has worn out. At that point, have a qualified service person inspect the unit. Ask them to show you the test results, the regeneration history, and what they measured. Keep your own records as well. Clear notes help you decide between cleaning, repair, or replacement, and they make every next conversation easier.