The Best Leak Detection Method for Your Situation

Which Leak Detection Method Is Right for You?

Finding a leak costs $75-$200 for a visual inspection, $150-$400 for acoustic detection, and $300-$600 for infrared thermography. There isn’t one best method, there’s a best method for your leak, and it depends on where the leak likely is and how hidden it is. Here’s how to match method to situation so you get an accurate result at the lowest cost that works.

If the Leak Is Visible or Easily Traced

You need a visual inspection ($75-$200), the simplest, cheapest method. A basic check of accessible areas suffices when the leak is out in the open or you can follow a stain to its source. Don’t pay for advanced imaging when your eyes and a plumber’s experience can find it. For accessible leaks, visual is the right, economical choice, and it’s sometimes even included in a standard service call, making it effectively free when a plumber’s already on site.

If the Leak Is Inside a Wall or Floor

Acoustic detection ($150-$400) is the match. Acoustic equipment listens for the sound of water escaping inside walls and floors, pinpointing a leak you can hear evidence of (running water with everything off) but can’t see. For a leak sealed behind a finished surface, acoustic listening locates it without tearing the wall open to hunt, which is exactly the destructive, expensive guessing you want to avoid. It’s the sweet spot of cost and capability for hidden-but-not-buried leaks. (For more on this, see What Makes Leak Detection Cost More (or Less)?.)

If It’s a Slab or Underground Leak

Infrared thermography ($300-$600) is built for this. Thermal imaging detects the temperature differences that moisture creates, making it the tool for the hardest-to-find hidden leaks, especially those under a slab or underground where you can’t see or easily hear them. It costs the most, but for a leak this elusive, it’s what prevents blind, destructive digging, and cutting concrete in the wrong spot is far more expensive than the infrared fee. Here, the priciest method is also the most cost-effective, because the alternative is so destructive. (For more on this, see Slab Leak Detection: What Homeowners Need to Know.)

If You Only Suspect a Leak From a High Bill

Start free, then escalate. Before booking any method, run a DIY water-meter test (all water off, watch the meter) to confirm a leak exists. If confirmed but you can’t locate it, the pro will choose a method based on the likely location, often starting with a visual or acoustic check and moving to infrared only if needed. This staged approach keeps you from paying for the most advanced method before it’s clear you need it. (For more on this, see Acoustic vs. Thermal vs. Tracer Gas Leak Detection.)

If the Leak Is Intermittent or Elusive

Choose a pro with multiple methods rather than a single tool. A leak that comes and goes, or hides well, may need more than one approach. A pro equipped with visual, acoustic, and infrared can escalate as needed to find it, which is more valuable here than any single method. The “best method” for an elusive leak is really “a pro who has all the methods and the experience to know when to switch.”

If the Leak Is on a Pressurized Supply Line

Some pros add a pressure or line-isolation test, isolating sections of plumbing and watching for pressure loss to narrow down which run is leaking, before or alongside acoustic and infrared work. If your situation is a suspected supply-line leak with no obvious location, ask whether they use pressure testing to narrow the search area first; it can make the acoustic or infrared step faster and cheaper by telling the pro where to focus. The idea is to work from broad to specific: a pressure test can reveal that the leak is on the hot line rather than the cold, or in the run feeding one bathroom rather than the whole house, and that alone can cut the acoustic or infrared search in half. Combining methods this way is often the mark of an experienced pro, they don’t reach for the most expensive tool first and sweep the entire home, they reason about where the leak is likely to be, confirm the general area cheaply, then bring the precise (and pricier) equipment to bear only on the narrowed zone. For a homeowner, the practical takeaway is to favor a pro who thinks in this staged way, because it tends to find the leak faster and at lower total cost than one who defaults to a single method for every job.

Matching Method to Situation

Visual for accessible leaks, acoustic for leaks in walls and floors, infrared for slab and underground leaks, pressure testing to narrow a supply-line leak, and a free meter test first to confirm any suspected leak. The right method finds your leak at the lowest cost that works, no overpaying for infrared on a visible drip, no missing a slab leak with a visual-only check. When you’re ready to connect with a pro who’ll match the method to your situation, use the button below. EPA WaterSense estimates the average household wastes about 9,300 gallons a year to leaks, and a single dripping faucet more than 3,000 gallons.