Quick answer
Water leak detection is the process of locating unwanted water loss in a plumbing system or building. A hidden leak can occur under a slab, inside a wall, around a fixture, in an outdoor supply line, or in another location, so the first step is to narrow down the likely source.
Clues that water may be escaping
- A water bill increases without an obvious change in use
- The meter indicates flow when fixtures are off
- Persistent dampness, bubbling paint, or unexplained staining appears
- You hear water movement when the home is quiet and fixtures are off
- A musty smell persists without a clear source
The same symptoms can come from a running toilet, leaking appliance, roof, drainage issue, or condensation. Accurate diagnosis matters.
For broader context, see our guide to slab leak repair in San Antonio and the factors that shape the next step.
What to record before requesting help
- When you first noticed the issue and whether it is constant
- Which fixtures or appliances were operating
- Any meter observations made with water use stopped
- Photos of visible moisture or damage, if safe to take
- Whether the issue is near a fixture, exterior wall, or floor
Do not remove flooring, open walls, or cut concrete to search for a hidden pipe yourself.
Finding the right next step
- A fixture leak may need a targeted plumbing repair
- A suspected supply-line leak may need pressure testing or system isolation
- A possible slab leak may require specialized locating methods
- Water damage may require separate drying or restoration work
Explain the symptoms clearly so the provider can decide which inspection is appropriate.
Frequently asked questions
Can a water meter help identify a leak?
It can provide a clue. With all water use stopped, continued meter movement may indicate flow, but it does not show where the leak is or prove that it is beneath the slab.
Is water leak detection the same as slab leak detection?
Slab leak detection focuses on a suspected leak in or under the foundation. General water leak detection considers a wider range of possible locations and causes.
Should I shut off my main water valve?
If you believe an active leak is causing damage, shutting off the supply may help if you can do so safely and know how to operate the valve. Seek professional help if you are unsure or conditions are hazardous.
Local service and referral information
Availability depends on the independent provider and the property address. Ask about coverage, diagnostic fees, credentials, and the full work scope before making a decision. Our San Antonio slab leak repair information explains how detection, repair, and referrals fit together.
For nearby local context, visit our service-area guide. If the source of the water is not yet known, our water leak detection guide may also help.