Leak Detection Services
A hidden water leak can run for weeks or months before you see a single wet spot. By then the damage often reaches drywall, framing, flooring, and the water bill. Professional leak detection finds the exact source of a leak without tearing your home apart to look for it.
Find the Leak Before You Open a Wall
The Deston is a nationwide referral service. We connect homeowners across all 50 states with independent local plumbers who carry the listening equipment, infrared cameras, and moisture meters needed to pinpoint leaks fast. Most leaks are not dramatic. They hide behind walls, under floors, beneath concrete slabs, and along the main line in your yard.
A plumber with the right tools can trace a leak to within inches. That precision matters. It means one small access point instead of a wall full of exploratory holes. If you suspect a leak, call (888) 418-3086 and The Deston will connect you with a local plumbing pro who can find it.
The Deston is a referral service serving homeowners across all 50 states. We connect you with independent local plumbers. We do not perform plumbing work ourselves. You pay the plumber directly, and the plumber gives you upfront pricing before work starts.
Signs You Need Leak Detection
You do not have to see water to have a leak. Watch for these warning signs. Any one of them is a good reason to schedule a professional inspection.
Water bill climbs, no change in use
A sudden jump that you cannot explain is one of the most common signs of a hidden leak. Compare your current bill with the same month last year.
Running water sound, nothing on
Stand quietly near walls, floors, and fixtures. Hissing, trickling, or the sound of water moving through pipes when every faucet is off points to a leak behind a surface.
Damp spots, stains, bubbling paint
Yellow or brown stains on ceilings, peeling paint, warped baseboards, and soft spots in drywall all suggest water traveling where it should not be.
Mold or musty smells
Persistent mold growth or a damp, earthy odor in a room with no clear source often means moisture is feeding it from inside a wall or under a floor.
Hot spots on the floor
A warm patch on a concrete or tile floor can signal a hot water line leaking under the slab. Pets often find these spots first.
Low water pressure
If pressure drops across the house and the cause is not the municipal supply, water may be escaping through a break in the line before it reaches your fixtures.
Water meter runs, everything off
Shut off every faucet and appliance, then check the meter. If the dial or digital readout is still moving, water is leaving your system somewhere.
Soggy patches in the yard
A constantly wet area of lawn, even in dry weather, can mark the path of a leaking underground water line. Watch for unusually green or fast-growing grass in one spot.
Foundation cracks or settling
Water under a slab can wash soil away and let sections settle. New cracks near doors and windows, or doors that stick, deserve a leak check along with a foundation look.
How Leak Detection Works
Professional leak detection follows a careful process. The goal is always the same: find the leak with the least damage to your home.
- 1
Interview and visual inspection
The plumber starts by asking what you have noticed: bills, sounds, stains, smells. Then they walk the property looking for visible clues like discoloration, swelling, or corrosion on exposed pipes.
- 2
Moisture mapping
Using handheld moisture meters and probes, the plumber checks walls, floors, and ceilings for high moisture levels. These readings create a map that shows how far water has traveled and which direction it came from.
- 3
Infrared thermal imaging
An infrared camera reads surface temperatures. A leaking cold water line shows up as a cool patch. A leaking hot water line shows as a warm patch. The camera sees through drywall, tile, and flooring to reveal the outline of the problem without opening anything.
- 4
Acoustic listening
Specialized listening equipment picks up the sound of water escaping under pressure. Electronic amplifiers and ground microphones can detect leaks through concrete, soil, and walls. The plumber moves the sensor along the pipe path and zeroes in on the loudest point.
- 5
Pressure and isolation testing
To confirm which line is leaking, the plumber may pressure-test sections of the system. If pressure drops on one isolated section, that section holds the leak. For yard lines, this test can confirm a main line leak before anyone digs.
- 6
Camera confirmation
For drain-side leaks, a small camera on a flexible cable goes inside the pipe to show exactly what is wrong. On supply lines, the plumber may use a borescope through a tiny access hole to see the leaking joint or crack directly.
- 7
Marking and repair plan
Once found, the leak location is marked precisely. The plumber explains what failed, what the repair involves, and what it will cost before any work starts. You approve the plan before a single cut is made.
Types of Leaks and How Each Is Found
Not all leaks are alike. Different locations call for different detection methods.
Wall and ceiling leaks
Supply lines run through walls to reach fixtures. A pinhole in copper or a loose fitting can spray a fine mist inside the cavity for months. Infrared cameras and moisture meters locate these quickly. Repair usually needs only a small drywall opening once the spot is marked.
Slab leaks
These leaks sit in the water lines buried under your concrete foundation. Acoustic equipment is the main tool here, often combined with thermal imaging for hot lines. Slab leaks are their own repair specialty, with options like tunneling, rerouting, or direct access through the slab. Learn more on our slab leak repair page.
Underground water line leaks
The main line from the meter to your house can crack from soil movement, tree roots, or age. Ground microphones trace the sound along the pipe run. Pressure testing confirms the line is the problem before excavation starts. See water line repair for how these get fixed.
Drain and sewer leaks
Leaks on the drain side do not hiss, so cameras do the work. A sewer camera inspection shows cracks, separations, and root intrusion inside the pipe. This tells the plumber whether a spot repair or a larger fix is needed.
Fixture and appliance leaks
Toilets, dishwashers, washing machines, and water heaters can leak slowly at supply connections. Dye tests, moisture meters, and simple observation usually catch these. A plumber checks supply lines, shutoff valves, and drain connections during the visit.
Roof and exterior plumbing leaks
Hose bibs, irrigation lines, and outdoor faucets can leak underground or inside exterior walls. Seasonal checks catch most of these. Infrared scans work well here because the temperature difference between leaking water and the surrounding material is often large.
The Water Meter Test You Can Do Today
Turn off every faucet, appliance, and irrigation zone, then watch your water meter. If the dial or readout keeps moving, water is escaping somewhere in your system. Note the reading, wait 30 minutes without using water, and check again. Movement means a leak.
Next, narrow it down. Shut off the main valve to the house and check the meter again. If it stops, the leak is inside. If it keeps moving, the leak is in the yard line between the meter and the house. That one detail saves the pro time and saves you money on the visit.
Basic moisture meters and water alarms can alert you to a problem, but they cannot pinpoint a leak behind a wall or under a slab. Professional acoustic and infrared equipment, plus the training to read it, is what turns a guess into an exact location.
What Leak Detection Costs
Most homeowners pay between $150 and $400 for a professional leak detection visit. These are national ranges, not quotes. Always ask for upfront pricing before the visit.
| Job | Typical range |
|---|---|
| Standard leak detection visit | $150 to $400 |
| Complex cases: slab leak or underground line break, large lot | $400 to $800 or more |
| Most appointments, time on site | 1 to 2 hours |
Before and After: A Hidden Wall Leak
The photos below are illustrations of the difference pinpoint detection makes. They are not photos of a real job.
Before
AfterFrequently Asked Questions
How do I know if I have a hidden leak?
The clearest signs are a rising water bill, the sound of running water with everything off, damp spots or stains, musty smells, and a water meter that moves when no water is in use. Any one of these is worth a professional check.
Can a plumber find a leak without tearing up my walls?
Yes. Infrared cameras, acoustic listening equipment, and moisture meters locate most leaks to within inches. The plumber only opens the surface at the marked spot, which keeps the repair small and the cleanup simple.
How long does leak detection take?
Most appointments take one to two hours. Simple fixture or wall leaks can be found faster. Slab leaks and underground line leaks may take longer, especially on larger properties with long pipe runs.
What is the water meter test?
Turn off every faucet, appliance, and irrigation zone, then watch your water meter. If the dial or readout keeps moving, water is escaping somewhere in your system. Note the reading, wait 30 minutes without using water, and check again. Movement means a leak.
Does homeowners insurance cover leak detection?
Many policies cover the cost of finding and repairing sudden leaks, but coverage varies widely. Gradual leaks that ran for a long time are often excluded. Check your policy and document everything, including bills, photos of stains, and the plumber report.
Can I find the leak myself with a store-bought detector?
Basic moisture meters and water alarms can alert you to a problem, but they cannot pinpoint a leak behind a wall or under a slab. Professional acoustic and infrared equipment, plus the training to read it, is what turns a guess into an exact location.
What happens after the leak is found?
The plumber marks the exact spot and explains the repair: a small section replacement, a fitting fix, or a larger job like slab leak repair or repiping. You get upfront pricing and approve the work before anything is opened up.
Is a small leak really urgent?
Yes, if it runs for weeks. A pinhole drip can soak framing, feed mold, and add up on the bill. Small leaks are also cheap to fix when found early, and costly once the wall or floor has to be rebuilt.
Why does my bill jump but I see no water?
Supply leaks hide inside walls, slabs, and yard lines, so water never shows indoors. The meter test is the fastest way to confirm it, and acoustic or thermal tools then find the spot.
Do I need to be home for the visit?
Yes, at the start, to point out symptoms and give access. After that, most pros can work through the house and yard while you stay nearby for questions.
More Leak Help
Slab Leak Repair | Sewer Camera Inspection | Emergency Plumber | Whole-House Repiping | All Services
Your Bill Is Climbing and You Cannot See Why. Call Now.
Call now and we will connect you with a local pro who can run the meter test, scan the walls, listen under the slab, and mark the exact spot.
(888) 418-3086 Call NowThe Deston is a referral service that connects homeowners with independent local plumbers. We are not a plumbing company.