You can check your home for a hidden water leak in about an hour with six simple checks: read your water meter, test your toilets, look under sinks and around appliances, inspect walls and ceilings, check outdoor faucets and compare your water bills. If those checks point to a leak you can’t find, Mr. Plumbing’s leak detection service can locate it.
Hidden leaks are easy to miss because most plumbing runs inside walls, under floors and above ceilings. A leak can run for weeks before a stain or a smell gives it away. These checks help you catch one early.
1. Read Your Water Meter
Your water meter is the most reliable way to find out whether water is leaving your plumbing when it shouldn’t be.
- Turn off every faucet, and make sure no appliance that uses water is running, including the dishwasher, washing machine and ice maker.
- Find your water meter. In many Chicagoland homes, it is in the basement near where the water line enters the house.
- Look at the leak indicator, which is a small triangle or dial on many meters. If it is turning, water is flowing somewhere.
- For a slower leak, write down the meter reading, avoid using any water for one to two hours, and read the meter again. If the number has changed, you likely have a leak.
2. Test Your Toilets
A toilet with a worn flapper can leak water from the tank into the bowl without making much noise. To test a toilet, add a few drops of food coloring to the tank and wait 15 to 30 minutes without flushing. If color appears in the bowl, the toilet is leaking and needs repair. Repeat the test for each toilet in the house.
3. Look Under Sinks and Around Appliances
Check the cabinets under kitchen and bathroom sinks for damp wood, water stains or drips from the supply lines and drain. Then check around the water heater, dishwasher, washing machine and refrigerator ice maker line. Small drips at these connections are a common source of leaks that go unnoticed.
4. Inspect Walls, Ceilings and Floors
Walk through the house and look for signs of water that is coming from inside a wall, floor or ceiling:
- Stains or discoloration on ceilings, especially below bathrooms
- Paint that bubbles or peels
- Drywall that feels soft or looks swollen
- Flooring that is warped, loose or stained
- A musty smell or mold in one area
5. Check Outdoor Faucets and Hose Connections
Outdoor faucets can drip at the spout or leak at the hose connection. Before freezing weather arrives, disconnect garden hoses and check that each outdoor faucet shuts off completely. A faucet that keeps dripping, or a damp spot on the wall inside the house behind an outdoor faucet, should be checked by a plumber.
6. Compare Your Water Bills
Compare your recent water bills with the same months last year. If your bill has gone up and your household’s water use hasn’t changed, a hidden leak is a likely cause.
When to Call a Professional
Call a plumber if your water meter moves when no water is in use, if you see water stains you can’t trace, or if your bill keeps climbing. Mr. Plumbing’s leak detection service follows four steps: meter and pressure testing, isolation, acoustic detection, then thermal imaging and moisture testing. Those steps locate the leak before any repair begins, and you get up-front pricing before work starts.
If water is actively leaking, turn off your main water shut-off valve first. Our quick tip video shows how to find it.
Hidden Water Leak FAQ
How long should I wait when testing my water meter?
Wait one to two hours without using any water. A small leak may not move the meter’s main reading in a few minutes, but it will show up over a longer period.
What if my meter shows a leak but I can’t find it?
That usually means the leak is inside a wall, under a floor or in a line you can’t see. A professional leak detection visit uses pressure testing, acoustic equipment and thermal imaging to find it.
Can a leaking toilet raise my water bill?
Yes. A toilet that leaks from the tank into the bowl runs water all day, and that water shows up on your bill. The food coloring test in step 2 shows whether a toilet is leaking.
Need Help Finding a Leak?
Mr. Plumbing has served Crestwood and the Chicagoland area since 1972. Call 708-385-8607 or request service online.
