Buying or moving into a St. Peters home that already has a water softener can feel like a bonus, but an inherited unit is an unknown until you check it. The previous owner may have kept it running well, neglected it, or set it up for a different household. Spend the first week confirming what you have before you change anything.

Start with what you can see

  • Find the main shutoff, the softener's bypass valve, and the drain line before you need them.
  • Check that the bypass is in the softened position, not diverting water around the unit.
  • Look at the salt level and the brine tank. Note whether the salt sits in water or has formed a hard crust.
  • Confirm the display shows the correct time. A wrong clock can mean the unit lost power or was reset at some point.
  • Look for drips, damp floors, or staining around fittings and the brine tank lid.

Ask for what the previous owner knows

Ask the seller or the listing agent for any service records, the model name, and the install date. Ask what the regeneration settings were and whether anyone changed them after a water test. Write the answers down, since you will need them if a service visit is required later. Do not rely on memory of a conversation with a seller.

Confirm the hardness yourself

Public water reports for St. Peters describe the tap water as hard. A softener is meant to bring hardness down, and the local reports mention softened-water results, so a working system should land well below the raw tap reading. A simple home test kit gives a quick read, while a lab gives a more reliable one. Test the cold tap at the kitchen sink and a softened outlet. If your home has an unsoftened outlet, test that too, so you can see the difference the unit makes.

Check the settings against your household

Regeneration timing and salt dosing should fit how many people live in the home, how much water they use, and how hard the incoming water is. A setting from a household of a different size may waste salt or leave water too hard. Do not change settings based on a single test. Watch the unit for a couple of weeks, note any complaints about spots, soap scum, or scale on fixtures, and adjust in small steps. Scale on a water heater or on fixtures can be a sign the settings need another look.

If the home has a private well

Some St. Peters area homes rely on private wells. A softener does not confirm that well water is safe to drink, and it does not replace testing. Shallow wells in septic-dense areas can carry coliform bacteria, and deeper aquifers can contain naturally occurring radium and uranium. The uranium hotspot in alluvial groundwater near the former Weldon Spring chemical and ordnance site is documented, so a home near that area deserves its own testing plan. Ask the lab for the specific tests you need, and keep the sample results with your closing papers.

Decide what to do next

  1. If the unit runs and tests as expected, keep the settings, add the records to a binder, and set a calendar reminder to check the salt level monthly.
  2. If the unit is off, leaking, or the display is wrong, have it inspected before relying on it for your main supply.
  3. If the unit runs but the result is weak, adjust the settings in small steps and retest after each change.
  4. If the home is on a well, schedule the water tests before relying on any treated water for drinking.

St. Peters water can change with its source and the season, so treat the first week as a baseline. A written record now makes every later question easier to answer.