How Do Plumbers Know Where a Leak Is Coming From? A Guide to Plumbing Leak Detection

March 26, 2025

Leaks can be infuriatingly difficult to find. To make matters worse, the longer a leak goes undetected, the more damage it can do. Fortunately for home and business owners, an experienced plumber has various methods of leak detection, ensuring they find the leak’s source on their first visit. If you’ve ever wondered how plumbers find leaks, read on to learn about their high-tech tools and reliable methods.

Visual Inspection

Sometimes, a leak is easier to find than you might realize; you just have to know what to look for. Plumbers will begin leak detection and repair by visually inspecting the surrounding area, looking for mold, dripping water, stains, and other common signs. They’ll examine fixtures hooked up to your plumbing system to find the source of the leak. An expert plumbing contractor can often identify the leak with a simple visual inspection.

Water Pressure Testing

Water pressure testing, or isolation testing, is a low-tech method plumbers employ to identify leaks. They attach a pressure gauge to the faucet or fixture connection and use it to gauge the water pressure when the faucet is on, turning the water meter off to ensure an accurate reading. If the pressure drops, there’s a leak! A plumbing contractor will then go throughout your home, turning off different fixtures to isolate the leak’s source.

Video Pipe Inspection

A higher-tech leak detection method is video pipe inspection, which utilizes small cameras to examine the nooks and crannies of your plumbing system. This method allows plumbers to look deep within your plumbing system, under the foundation and behind walls. A video pipe inspection is used when a plumbing contractor needs to get into otherwise inaccessible areas.

They utilize waterproof, HD cameras equipped with LED lights to move through your pipes, looking for plumbing issues like cracks, corrosion, and ongoing leaks. Some cameras can even “mark” the location of leaks so plumbers can more easily complete plumbing repairs.

Thermal Imaging Cameras

Thermal imaging cameras employ infrared imaging to see behind walls and floors and are also helpful in examining hot water pipes. They can detect subtle issues like excessive moisture and temperature variations not visible to the naked eye, allowing plumbers to gain a more accurate image of your plumbing system. Since thermal imaging cameras can take in broad areas, they increase leak detection efficiency, speeding up the repair process.

Soil Probe

Soil probes, also called pipe probes, utilize audio frequencies to detect underground leaks in sewer lines or water mains. These leaks are particularly serious, as they can cause significant structural damage to your property if not repaired promptly. A plumbing technician will start by identifying wet soil splotches, then follow the assumed plumbing path with a soil probe to determine the leak’s source. Expert plumbers can estimate the leak’s depth and determine how to solve it, employing innovative techniques like trenchless sewer repair for efficient solutions.

Dye Testing

Dye testing is often used to find leaks in toilet or pool systems. It is non-invasive and utilizes high-visibility dyes to track and identify leaks along the water’s path. A plumbing technician applies the dye and observes the system’s flow, looking to see where the colored dye escapes through a crack in the pipes or loose valve connection. This method is helpful if a leak is well-concealed or otherwise tricky to find.

ProFlo plumbers employ a range of plumbing tools and techniques to locate the source of a leak and repair it, leaving your plumbing system as good as new! As a locally-owned business, we pride ourselves on providing exceptional customer service and lasting plumbing repairs. Call ProFlo today at 951-694-1300 or contact us online to schedule an in-person consultation.

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