How do you find a leak in an underfloor heating pipe?

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 UK's leading leak detection specialists, who's here to answer your questions and provide expert leak detection advice. Dave, today's question is one we hear constantly from homeowners, if you've got a leak in your underfloor heating, how on earth do you actually find it without ripping the whole floor up?

Dave

Yeah, it's a really common worry. People picture a full demolition job, and honestly, that's not what good leak detection looks like. The whole point is to pinpoint the leak precisely before anyone touches the floor.

George

So what's the first thing ADI does when an engineer turns up to a property with a suspected underfloor heating leak?

Dave

First thing is a pressure test on the heating circuit. You pressurise the pipework with water or nitrogen and watch whether it holds. If pressure drops, you've confirmed there's a breach somewhere in the loop. That tells you the leak is real, not just a faulty valve or a loose fitting at the manifold.

George

Right, so you know there's a problem. Then what?

Dave

Then acoustic detection comes in. Acoustic leak detection works by picking up the sound signature that escaping water or gas creates as it forces through a breach in the pipe wall under pressure. We use highly sensitive ground microphones and contact sensors placed directly on the floor surface, and the equipment amplifies those frequencies so the engineer can actually hear where the signal is strongest.

George

Does that work through concrete screed? Because a lot of underfloor heating systems are buried pretty deep.

Dave

It does, yes. Acoustic equipment picks up leak noise through screed, concrete and floor coverings, tiles, timber, even some carpets. The signal attenuates the further you get from the source, so an experienced engineer moves the sensor methodically across the floor and maps where the sound peaks. That peak is your leak location.

George

And I've heard thermal imaging mentioned alongside acoustic, are they doing different jobs?

Dave

They complement each other. Thermal imaging cameras detect temperature differences at the floor surface. When a pipe leaks, the water spreads through the screed and changes the thermal pattern above it, you get a cool patch, or sometimes a warmer zone depending on whether the heating is running. Thermal imaging gives you a broad picture of where moisture has tracked to; acoustic detection then narrows it down to the actual breach point.

George

So you'd use both on the same job?

Dave

Often, yes. On a straightforward system in a new build with plastic pipe in screed, acoustic alone can be enough. But on an older property, or where the floor covering is thick or the leak rate is very slow, thermal imaging gives the engineer a wider view first. ADI engineers assess the construction and the leak rate on site and decide which combination makes sense.

George

What about tracer gas, I've seen that mentioned for underfloor leaks as well.

Dave

Tracer gas is particularly useful when the leak is very small and the acoustic signal is weak. ADI's engineers introduce a mix of nitrogen and hydrogen into the heating circuit, and that gas escapes through the same breach the water is escaping through. A gas detector at the surface then picks up exactly where the gas is coming through, which pinpoints the pipe breach to within a few centimetres.

George

That's remarkable precision. So between acoustic, thermal imaging and tracer gas, the engineer can find the leak without the homeowner needing to lose their entire floor?

Dave

Exactly. The whole value of proper leak detection is that you make one small, targeted opening, sometimes just a core hole to inspect the pipe, rather than lifting metres of floor on a guess. Acoustic detection, thermal imaging and tracer gas each give the engineer a different layer of information, and combining them means the repair contractor knows precisely where to cut.

George

Dave, that's really useful. So if anyone listening has a cold patch on their underfloor heating, a rising water bill, or pressure dropping on their heating circuit, they know what the process looks like now. ADI Leak Detection are specialists in exactly this kind of residential work, and as one of the UK's most trusted names in non-invasive water leak detection, they're the people to call before anyone starts breaking up your floor. Thanks Dave, and thanks to all of you for listening.

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.