A water meter can reveal a leak you cannot see, hear, or find with a flashlight. Many homes in and around St. Louis keep the meter in a basement, a utility closet, or a small box near the sidewalk. Reading it and running a simple no-use check takes only a few minutes, and the result tells you whether to keep searching inside the house or call for help outside it.
Locate and read your meter
Find the meter and any remote reading display attached to it. Some meters have a rolling dial with a small test hand that spins whenever water moves, even a slow trickle. Others show a digital readout. Write down the main reading along with the date and time. A photo works well too, as long as you can compare it later.
Run a no-use check
- Turn off every faucet, the dishwasher, the washing machine, and the ice maker.
- Make sure no one flushes a toilet, runs a shower, or starts an outdoor sprinkler during the test.
- Wait long enough that a normal household would have used some water, then read the meter again.
- Compare the two readings. Any change while everything is off points to a leak.
Read the result
If the test hand is still and the readout did not change, the plumbing is probably tight. If the reading moved, water is leaving the system somewhere. Next, find the main shutoff valve inside the house, usually near the water heater or where the supply line enters the home. Close it only if you know how to reopen it and the handle moves smoothly. Old valves can be stiff, and forcing one can break it.
With the house main closed, check the meter again. If it stopped, the leak is inside the house. If it still moves, the leak is between the meter and the main valve, which means the service line or the meter connections.
Common hidden leak spots in St. Louis homes
- A toilet flapper that does not seal, which can leak with no sound at all
- A supply line behind a washing machine or under a sink
- A water heater drain valve or fitting in a utility closet
- A tub or shower valve that drips into a wall cavity
- The service line from the street to the house, which can leak underground
To check the toilet, add food coloring to the tank, wait without flushing, and then look at the bowl. Color in the bowl means water is slipping past the flapper.
When the leak is outside the house
If the meter keeps moving with the house main closed, do not start digging in the yard. Contact your water provider, describe what you found, and share your readings, dates, and whether the flow stopped when the main was closed. They can check the line and explain which section is their responsibility and which is yours, since that depends on the property and where the line runs. Wet spots in the lawn, soft ground, or a sudden jump in your bill can all support the report.
What to do next
- Read the meter and write down the number and time.
- Run the no-use check with every fixture off.
- Test the toilet with food coloring and inspect any visible supply lines.
- If the meter still moves with the house main closed, call your water provider.
- Keep your readings so you can confirm the leak is fixed after repairs.
Clear records make it easier for a plumber or your water provider to pinpoint the problem quickly, whether it is a worn flapper in a St. Louis bathroom or a line running under the street.