If you have been away from home for a while, the water in your under-sink reverse osmosis system may not taste the way it did when you left. Water that sits still in a storage tank and small lines can change in taste or smell. This guide covers simple checks for St. Louis homes before you drink from the RO faucet again.
Why Stored RO Water Can Change
An RO system makes treated water slowly and keeps a supply in a storage tank under the sink. When the house is empty, that water does not move. Over time it can pick up faint odors from the tank, the tubing, or the faucet, and the taste may feel flat or slightly off. Warm weather in a closed-up St. Louis kitchen can make this more noticeable. A change in taste is a reason to check, not a reason to guess at the cause.
Checks Before You Drink
- Look at the storage tank and its fittings for drips, damp spots, or a soft feel.
- Check the RO faucet and the drain line below the sink for moisture or staining.
- Confirm the feed water shutoff is open and the RO system's own valves are in their normal positions.
- Run the RO faucet until the flow looks steady and normal.
- Smell and taste the water after it has run through, not the first bit that came out of the tank.
What to Look For
Pay attention to how the water looks. Clear water with a faint smell that clears after a good run is common after time away. Cloudy water, visible specks, or a smell that stays strong after running deserve a closer look. Note whether the change happens only at the RO faucet or also at your regular cold tap, since that tells you whether the problem sits in the RO system or in the home's supply.
Cold Tap Comparison
Compare the RO water with cold water from another tap in the house. If both are off, the issue may be in the supply or in a plumbing run that sat unused. If only the RO water is off, focus on the storage tank, the post-filter, and the faucet.
Filter Dates
Check the install date or last change date you wrote down for each filter. Time away does not pause a filter schedule, and a filter past its planned change is a common reason for a taste change. If you did not record the dates, read the date codes printed on each cartridge.
When to Stop Using the Water
If the water has a strong chemical odor, visible discoloration, or signs of a leak that may have been wet for a long time, stop drawing from the RO faucet. Use water you trust for drinking and cooking until you have run the checks above and found the cause. For questions about the city supply in St. Louis, contact your water provider's customer line and ask what conditions they have recently reported in your area.
Keeping Notes for Next Time
Write down the date you left, the date you returned, and what you saw when you checked. A short note makes the next trip easier to plan and gives you a record if the same thing happens again. Keep it with your filter dates so the whole system is in one place.