Acoustic vs Thermal Leak Detection: Which Finds Your Leak?

How acoustic detection works

Pressurised water escaping a pipe generates sound. Sensitive microphones and listening equipment find where that sound is strongest along the pipe's route, which is normally at or near the leak. It works through floors, walls and soil, and needs no temperature difference at all.

• Best for: pressurised supply leaks, slab and underground lines
• Weakened by: background noise, deep runs, some plastic pipes, very small leaks

How thermal imaging works

An infrared camera images surface temperatures. A hot-water leak warms the material above it; evaporating moisture can cool a surface. The resulting pattern can reveal a leak's location and the spread of moisture — but the camera measures temperature, not water, and patterns from sun, ducts or insulation gaps can look similar.

• Best for: hot-water lines, warm-floor slab leaks, moisture patterns in walls and ceilings
• Weakened by: cold-water leaks at ambient temperature, sunlight, heating systems

A side-by-side summary

Choose acoustic first when the suspect is a pressurised line and the environment is reasonably quiet. Choose thermal first when the clue is a warm floor, a ceiling stain or a hot-water line. Choose both — sequentially, confirming each other — when the first method's result needs verification, which is often.

The honest answer: method follows evidence

Professionals do not marry one tool. The meter test and isolation come first; the symptoms point to a method; the method's result is checked against the building and, where the stakes justify it, against a second method or tracer gas. Anyone who guarantees one method finds every leak is selling, not diagnosing.

Frequently asked questions

Need help with this at your property? See Thermal Imaging Leak Detection or request leak detection service.