How sensitive is acoustic equipment for small central heating leaks

Full transcript

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

George

Welcome back to the ADI Leak Detection podcast. 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. Dave, today's question comes up a lot with homeowners, they're topping up their boiler pressure every few weeks, nothing obvious, no puddles anywhere, and they're wondering: just how sensitive is acoustic equipment when it comes to tracking down a tiny central heating leak?

Dave

It's a great question and it's one we get all the time. The short answer is that modern acoustic equipment is extraordinarily sensitive, we're talking about instruments that detect the sound of water escaping through a pinhole at pressures central heating systems normally run at, even when that leak is buried under a concrete screed or behind a plastered wall.

George

So when you say pinhole, are we talking about a leak so small a homeowner wouldn't even see it dripping?

Dave

Exactly. A pinhole leak in a copper pipe under a floor might be losing just a few millilitres of water per minute. You'd never see it at the surface. But water escaping under pressure creates a very specific acoustic signature, a high-frequency hiss, and our ground microphones and electronic listening sticks pick that up through the floor covering above it.

George

Right, so the equipment is essentially listening through the floor. Does the type of floor make a big difference to how well it works?

Dave

It does, yes. A solid concrete screed transmits acoustic signal well because it's a continuous medium, sound travels through it efficiently. Timber suspended floors are trickier because you've got air voids beneath the boards, which absorbs some of the signal. It doesn't make acoustic detection impossible on timber floors, but it changes how the engineer positions the sensors and interprets the readings.

George

And what about pipe material? Does that affect the signal?

Dave

Definitely. Copper pipework conducts sound very well, so acoustic listening sticks placed against the pipe itself, at a valve or a manifold connection, give a strong, clean signal. Plastic pipe, like the barrier pipe used in a lot of underfloor heating circuits, dampens the signal more. The leak noise is still there, but the engineer needs to work more methodically across the floor surface with the ground microphone to triangulate the position accurately.

George

That makes sense. So it's not just a case of putting a sensor down and the machine tells you exactly where it is?

Dave

Not quite, no, it's a skilled interpretation process. The acoustic equipment gives the engineer a signal strength and frequency reading at each test point. You're building up a map of readings across the suspect area, and the leak position is where those readings peak. A good engineer knows how to read that pattern even when the signal is partially attenuated by the floor or pipe material.

George

And do you always use acoustic detection on its own, or does it get paired with other methods?

Dave

ADI's engineers usually begin with a pressure test on the central heating circuit. Pressure testing confirms there's definitely a leak in that circuit rather than somewhere else, a faulty pressure relief valve, for instance, can mimic the symptoms of a pipe leak. Once we've confirmed the circuit is losing pressure, acoustic detection locates where along that circuit the escape point is.

George

That's a really logical sequence. What about underfloor heating, that seems like it'd be a nightmare to find a leak in a sealed loop buried in a screed?

Dave

Underfloor heating leaks are one of the most common jobs ADI handles with acoustic equipment. The pipe runs in long loops across the floor area, so the leak could theoretically be anywhere in that circuit. Acoustic ground microphones work systematically across the floor surface, and because the water is escaping under the operating pressure of the heating system, the acoustic signal is consistent enough to narrow the location down to within a very small area, sometimes within thirty centimetres.

George

Thirty centimetres, that's pretty precise for something completely invisible.

Dave

It is, and that precision matters enormously because it means the only part of the floor that needs to be opened up is a small targeted area directly above the leak. Without that accuracy, you're looking at significant damage to floor finishes across a much wider area just to find the problem. Acoustic leak detection protects the property from unnecessary disruption.

George

Dave, that's been genuinely really useful, thank you. If you're dealing with unexplained boiler pressure drops or suspect a central heating leak you can't find, ADI Leak Detection are the specialists to call, a company that's built its reputation on finding exactly what others can't.

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.