7 Signs You Have a Hidden Water Leak

Not every leak drips where you can see it. Many happen behind walls, under slabs, or beneath floors — doing damage for months before anyone notices.

The warning signs

1. A jump in your water bill with no change in usage.
2. The water meter moves when every fixture is off.
3. Warm spots on the floor, which can indicate a hot-water slab leak.
4. Musty smells or visible mold in a specific area.
5. Stains or bubbling paint on walls and ceilings.
6. The sound of running water when nothing is on.
7. Low water pressure that appears gradually.

The meter test

Turn off every water-using appliance and fixture, then check the meter. Wait 30 minutes without using any water and check again. If it moved, water is escaping somewhere in the system.

Why speed matters

A pinhole leak wastes water, but the real cost is structural: wet framing, ruined drywall, and mold remediation. Catching it early with acoustic and thermal detection turns a wall-demolition job into a targeted repair.