What are the signs of a slab leak?
Slab leaks hide, but they leave clues. Look and listen for these signs.
- A higher water bill with no change in how you use water
- The sound of running water when every fixture is off
- Warm or hot spots on the floor, which can point to a leaking hot water line
- Damp carpet, lifting flooring or a musty smell
- Cracks in walls or floors, although these can have other causes
- Low water pressure at several fixtures
A simple home test helps. Turn off every fixture and appliance, then look at your water meter. If the dial or low-flow indicator still moves, water is going somewhere. A water heater problem can look similar, so check that first. Our water heater page lists those signs.

