How to Find Where a Water Leak Is Coming From

To find a hidden water leak, start by confirming there is one — check your water meter with everything off — then narrow it down by the signs: where the stains, damp spots, or musty smells are. Most home leaks trace back to plumbing, a roof, an appliance, or the AC, and each leaves its own clues.

Signs you have a hidden leak

• A water bill that jumped with no change in use.
• Stains or bubbling paint on walls or ceilings.
• A damp, musty smell in one area.
• Warm spots on the floor (a possible slab hot-water leak).
• The sound of running water when nothing’s on.

Check your water meter

Turn off every water fixture and appliance in the house, then look at your water meter. If it’s still moving, water is going somewhere it shouldn’t — you have an active leak. This simple test confirms a leak before you go hunting for it.

Common sources to check

Work through the usual suspects: under sinks and around toilets, the water heater, behind the washing machine and dishwasher, the AC condensate line and attic unit, and the roof after rain. A leak can travel far from its source, so the stain isn’t always above the problem. (A burst or failing pipe inside a wall is a common hidden culprit.)

When to call a professional

If the meter says you have a leak but you can’t find it, it may be inside a wall, under the slab, or underground — that needs electronic leak detection. And if a leak has already caused staining, damp drywall, or a musty smell, get the moisture dried out before it grows mold, which can start in 24–48 hours here.

Found a leak that’s already done damage? Get it dried before mold starts. Call (713) 422-2550 — Houston, 24/7.

Frequently asked questions