How to Find a Hidden Water Leak in Your Home

Start with the Water Meter Test

Turn off every faucet, appliance and irrigation zone in and around the house. Make sure the washer, dishwasher and ice maker are not running. We often point homeowners to the EPA leak detection checklist, starting with the two-hour water meter test.

Find your water meter, usually in a box near the street, and write down the reading or take a photo. Many meters also have a small triangle or dial that spins when water is flowing.

Wait 15 to 30 minutes without using any water, then check the meter again. If the numbers moved or the flow indicator is spinning, water is leaving the system somewhere.

To narrow it down, close the main shut-off valve at the house and watch the meter again. If it stops moving, the leak is inside the house. If it keeps moving, the leak is in the service line between the meter and the house.

Other Signs of a Hidden Leak

Watch for a water bill that climbs without a change in how you use water, the sound of running water when everything is off, damp or warm spots on floors, musty odors, warped flooring, peeling paint and water stains on walls or ceilings. A patch of unusually green grass or soggy ground in the yard can point to a service line leak.

Where Leaks Usually Hide

Toilets

A running toilet is the most common hidden leak and can waste a surprising amount of water. Put a few drops of food coloring in the tank and wait 15 minutes without flushing. If color shows up in the bowl, the flapper is leaking. Our toilet and faucet repair service handles that in a single visit.

Under Sinks and Behind Appliances

Check supply lines and shut-off valves under sinks, behind the washing machine, at the refrigerator ice-maker line and around the water heater.

Inside Walls and Ceilings

Leaks in supply lines or drain pipes inside walls show up as stains, soft drywall or bubbling paint, usually below a bathroom.

Under the Slab

In slab-on-grade homes, a leak in a line under the foundation may show up as a warm spot on the floor, cracks in flooring or the sound of running water with every fixture off.

The Service Line and Irrigation

Leaks between the meter and the house, or in sprinkler lines, often show up as wet patches in the yard.

When to Call for Leak Detection

If the meter test shows a leak and you cannot find it, the next step is professional detection. Our leak detection and slab leak repair team uses acoustic listening equipment, pressure testing and thermal imaging to pinpoint the source without opening up walls and floors on a guess.

Once the leak is located, we repair it through our water and pipe leak repair service. If leaks keep happening in different places, we will also talk through whether the pipes are near the end of their life.

How to Prevent the Next Hidden Leak

Most hidden leaks start at a small, predictable failure point. Replace rubber washing machine hoses with braided stainless lines, and swap out aging supply lines under sinks and toilets before they crack. Check the area around the water heater and under sinks every few months for drips or stains.

Keep an eye on water pressure as well. Pressure above about 80 psi strains every pipe, fitting and appliance in the house, and most plumbing codes call for a pressure-reducing valve when street pressure runs that high. A quick gauge test at an outdoor spigot tells you where you stand, and our plumbing inspections include it.

If Water Is Actively Spreading

Shut off the main water valve and call our 24/7 emergency plumbing line. Stopping the water quickly is the single biggest factor in how much damage a leak does.

Find It Before It Spreads

If your bill is up or the meter keeps moving, we will locate the leak and give you a written quote for the repair. Call Trussville Plumbing at 205 537 0689.