Stop Guessing Where the Leak Is — Call Masters Plumbing Service in Monrovia, CA
The difference between a $300 pipe repair and a $3,000 drywall-and-remediation project is often just whether the leak was found before or after excessive wall opening. Our Leak Detection service in Monrovia uses the same detection methods utilities and insurance adjusters rely on — to pinpoint the failure location before anything is cut.
4 Detection Capabilities We Bring to Every Leak Detection Call
A pressure test tells us a leak exists and how much water is escaping. Detection equipment tells us precisely where.
🎙️
Acoustic Ground Microphone
Acoustic detection is most effective on metal pipe (copper, cast iron) under slab or in concrete — materials that conduct sound efficiently. It works in quiet environments and requires shutting off the house briefly to establish a clean acoustic baseline.
🌡️
Infrared Thermal Camera
Active water leaks — hot or cold — create a temperature differential on the surfaces they contact. An infrared camera shows these differentials as color-coded heat maps, revealing the wet zone inside a wall or under a floor without any cutting. A cold water leak behind drywall appears as a spreading blue-gray cool zone; a hot water leak shows the inverse.
📉
Pressure Decay Testing
Pressure decay testing is the standard by which we confirm a leak is present before committing detection equipment time. It also tells us approximately how significant the leak is — a rapid pressure drop vs. a slow one indicates the size of the escape point.
💨
Tracer Gas Detection
For leaks that don't produce sufficient acoustic signature — very slow leaks, polyethylene pipe, or leaks deep under concrete — we can introduce a nitrogen/hydrogen tracer gas mixture into the isolated pipe and use a calibrated gas detector at the surface to find where the gas escapes. The detection sensitivity can locate leaks that produce no discernible pressure drop during a standard timed test.
What We Locate
Hidden Leak Types We Find and Document
Our detection service covers the full property, not just the obvious locations.
Under Slab
Slab Leak Detection
Supply lines run under or through the concrete slab in most slab-on-grade homes. When these lines fail — from corrosion, shifting, or manufacturing defects — the leak is invisible from the surface but audible to acoustic equipment. We walk the floor on a grid pattern, map the loudest detection points, and triangulate to a specific floor location, typically within a square foot.
In-Wall
In-Wall & Ceiling Leak Detection
We document the thermal anomaly, mark the approximate pipe location, and recommend a minimal access cut rather than a wide wall opening.
Water Main
Underground Supply Line Detection
We mark the ground above the detected leak location so the repair crew opens only the section they need to.
Pool & Irrigation
Pool Line & Irrigation Leak Detection
Irrigation system leaks in main supply lines and lateral runs are found by isolating zones with the irrigation controller and pressure-testing each zone individually. Zone by zone testing narrows the failure to the smallest possible section.
Commercial
Commercial Property Leak Detection
Commercial water loss from undetected leaks often shows up as elevated utility bills for months before physical evidence appears. We can assess a commercial building's plumbing system for suspected leaks at the property owner's or property manager's request.
Documentation
Leak Detection Report for Insurance
Insurance claims for water damage from hidden leaks typically require documentation that the leak was not visible or detectable without specialized equipment. Our detection report includes: pressure test results confirming active water loss, detection method used, thermal imagery or acoustic mapping showing leak location, and technician certification information.
How Our Leak Detection Process Works in Monrovia, CA
Here's exactly how a Masters Plumbing Service leak detection call plays out.
1
Initial Water Loss Confirmation
We start at the meter. All fixtures off, we watch the meter for 10 minutes. Movement confirms active water loss from the supply side. We also check for any visible evidence — water stains, soft floors, moisture readings with a moisture meter at suspect wall surfaces.
2
Zone Isolation & Pressure Decay
Zone isolation is the step that turns "there's a leak somewhere in the house" into "the leak is on the hot side supply, between the water heater and the master bath."
3
Detection Equipment Deployment
We document findings with thermal images and note detection readings at multiple grid points to triangulate the strongest signal.
4
Written Report & Repair Options
Insurance claims: the report is formatted to support a claim for water damage from a concealed leak. We can provide supplemental documentation on request.
Customer Reviews
Real Leak Detection Reviews from Monrovia
★★★★★
My water bill doubled over three months with no change in usage. Masters Plumbing Service came out, confirmed the meter was moving with everything off, isolated the cold supply to the kitchen as the failing branch, and used the acoustic device on the slab to pinpoint a location 4 feet from the outside wall under the kitchen floor. The repair crew opened a 10-inch circle in the tile, found a pinhole in a copper elbow exactly where detection said it would be. I was skeptical acoustic detection was that precise — it was.
— C. Thornton, Monrovia
★★★★★
Our insurance company required professional leak detection documentation before approving the claim. Masters Plumbing Service's written report with pressure test data and thermal imagery was exactly what the adjuster needed. Claim approved. The detection cost was covered as part of the claim.
— B. Osei, Monrovia, CA
★★★★★
Commercial building where water costs were running 40% above baseline for six months. Masters Plumbing Service ran a systematic zone-by-zone pressure isolation across four floors, narrowed the loss to the third-floor kitchen supply branch, and located the failure with thermal imaging at a concealed valve body in the ceiling. No damage to the finished ceiling.
— T. Anand, Monrovia, CA
Common Questions
Leak Detection Questions from Monrovia, CA Property Owners
The most reliable self-check: shut off every fixture and appliance in the house, then watch the water meter for 15 minutes. Any movement — including the small leak indicator dial — means water is escaping the supply side somewhere. If the main meter dial moves with everything off, you have a leak. Call us to locate it.
The repair itself requires physical pipe access, which typically means a small, targeted opening. But that's a completely different proposition from opening large wall sections while searching for an unknown leak location.
For leaks in plastic pipe, low-pressure situations, or high-noise environments, accuracy may be lower and tracer gas becomes the preferred supplemental method.
Yes. Our written detection report includes: technician credentials, equipment identification, pressure test methodology and results, detection method description, leak location with reference measurements, and supporting thermal imagery. This is the documentation format most insurance adjusters require to approve a concealed-leak water damage claim.
A standard residential leak detection — confirming water loss, isolating the failing zone, and deploying detection equipment to locate the failure — typically takes 1.5–2.5 hours. More complex scenarios (multi-zone commercial, large properties, very slow leaks requiring tracer gas) can run 3–4 hours.
The repair quote is given before any wall or floor is opened. You know the full cost of detection + repair before anything is cut.
Service Area
Leak Detection Available Across Monrovia, CA
Masters Plumbing Service provides professional Leak Detection for residential and commercial properties throughout Monrovia and the surrounding Monrovia, CA service area. Detection appointments available most weekdays and Saturdays.
