Can acoustic detection find a pinhole leak in a concealed heating pipe?

Full transcript

George and Dave in conversation. Every word of the episode, exactly as recorded.

George

Welcome to the show. I'm here with Dave from ADI Leak Detection, the country's leading name in leak detection, who's here to answer your questions and provide expert leak detection advice. Today's question is one I hear a lot from homeowners: can acoustic detection actually find something as tiny as a pinhole leak inside a concealed central heating pipe?

Dave

Short answer, yes, it can, and it does it pretty reliably. A pinhole in a pressurised heating pipe forces water through a very small gap at speed, and that creates a distinctive noise. Acoustic leak detection equipment picks up that sound signature even when the pipe is buried under a concrete screed or hidden inside a stud wall.

George

So we're literally listening for the leak? I'd have thought a pinhole would be almost silent.

Dave

That's what most people assume, but the physics works in our favour. The pressure difference across that tiny hole produces a turbulent flow, and turbulence generates noise across a wide frequency range. Our acoustic sensors are sensitive enough to detect that signal through several centimetres of concrete. The pipe itself also conducts sound, it acts almost like a wire carrying the noise along its length.

George

Does the pipe material make a difference? Because a lot of older houses have copper, but newer ones might have plastic underfloor pipework.

Dave

It makes a real difference to the signal character, yeah. Copper transmits the leak noise very efficiently, sound travels a long way along a copper pipe, which actually helps us narrow down the location quickly. Plastic pipe, by contrast, absorbs more of the signal. The noise doesn't travel as far, so our engineers need to take more readings at closer intervals to triangulate the exact spot.

George

And what about the flow rate? Does a very slow seep from a pinhole produce enough noise to detect?

Dave

Flow rate and system pressure together determine how strong the acoustic signal is. A central heating system typically runs at one to one-and-a-half bar, and that pressure pushing water through a pinhole generates a consistent signal even when the visible loss is only a drip or two per minute. A gravity-fed system at lower pressure is harder to read, but still detectable with the right equipment and technique.

George

So how does the survey actually work when ADI comes out to a property? Walk me through what the engineer does.

Dave

The engineer starts by confirming there's an active leak, checking the system pressure, looking at the expansion vessel, ruling out obvious above-ground sources. Once we know the loss is in the concealed pipework, we map where the pipes run using pipe-tracing equipment. Then acoustic sensors go onto the floor surface at measured intervals along those pipe runs, and we listen.

George

And you can hear the difference between a leak and, say, normal flow noise from the system?

Dave

Absolutely. A trained engineer knows the acoustic fingerprint of a pressurised leak versus normal circulation. The leak produces a characteristic hiss or high-frequency turbulence that stands out from background noise. We compare signal strength across multiple sensor positions, the readings peak directly over the leak, and that's where we focus. We'll often combine acoustic detection with thermal imaging on the same visit. Thermal imaging detects the temperature contrast where water escapes from a hot heating pipe and spreads into the surrounding floor structure. The two methods together give us a very precise fix on the leak's position.

George

That's really reassuring, because the thing homeowners dread is someone smashing up their floor to find a leak that turns out to be somewhere else entirely.

Dave

That's exactly what non-invasive detection is designed to avoid. ADI's engineers pinpoint the leak's position to a small enough area that any access needed is targeted and minimal. In a lot of cases, a single core drill or a small section of lifted tile is all that's required rather than ripping out an entire floor run.

George

Dave, that's been genuinely useful, thank you. If you're dealing with a suspected pinhole leak in your heating pipework and you don't know where to start, ADI Leak Detection are among the most trusted specialists in the UK for exactly this kind of residential work. Worth getting them in before anyone touches a single tile.

How this episode was made. This episode was produced using AI-generated voices and script, based on real leak detection questions and the working knowledge of ADI Leak Detection engineers. More about how the podcast is made.