Can leak detection tell if damp is from a cold or heating pipe?

Full transcript

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

George

Welcome back. 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 comes from a homeowner who's got a damp patch on their ground floor and they genuinely don't know whether it's their cold water supply or their heating system that's leaking. Can a leak detection survey actually tell the difference?

Dave

Yes, it can, and that distinction matters more than people realise. The repair route for a cold water supply leak is completely different to what you'd do with a heating circuit leak, so getting that wrong from the start costs time and money.

George

So how does the survey approach that? Where do you even begin when you've just got a wet patch and no obvious source?

Dave

We start with thermal imaging. A heating pipe carries water at a much higher temperature than a cold supply line, so a thermal imaging camera will show a heat signature along the pipe run if it's the heating system leaking. Cold supply pipes sit at ground temperature, so they don't produce that same signature. That single check often narrows it down straight away.

George

That's quicker than I'd have expected. But what if the damp patch isn't directly above the pipe, or the leak has travelled along the slab?

Dave

That's where acoustic detection comes in. Acoustic leak detection equipment picks up the sound that escaping water makes as it pushes through a crack or a pinhole. Cold water supply pipes are pressurised constantly, so they produce a very consistent noise profile. Heating circuits are pressurised differently and the acoustic signature reflects that.

George

So the equipment is actually hearing a difference between the two pipe types?

Dave

Exactly. An experienced engineer reads those acoustic signals and the frequency pattern helps identify which system is the source. We also carry out isolation tests, where we shut down one system at a time and listen again. If the acoustic signal drops when the heating is off but stays present with the cold supply running, that tells you which pipe is leaking without any guesswork.

George

What about pipes under a solid concrete floor? Because a lot of these ground floor damp patches are right above a screed.

Dave

That's where tracer gas comes in. ADI's engineers inject a safe gas mixture into the pipe under test, and tracer gas detection equipment locates exactly where that gas escapes through the floor surface. We can do this on the cold supply or the heating circuit in isolation, so again we're building a clear picture of which system and precisely where the leak sits.

George

So you're not just telling the homeowner which pipe is leaking, you're also giving them a precise location before anything gets dug up?

Dave

That's the whole point of the survey. A plumber or heating engineer needs to know the pipe type and the location to plan the repair properly. If we hand them a report that says the heating flow pipe has a pinhole at a specific point under the floor, they can make a targeted repair rather than lifting a large section of screed.

George

Are there cases where it's genuinely ambiguous, where both systems run close together and the damp could be either?

Dave

It does happen, particularly in older properties where cold supply and heating pipes share a similar route beneath the floor. In those cases we work through each system methodically, isolating and testing one at a time. Thermal imaging, acoustic equipment, and tracer gas used together give us enough data to reach a clear conclusion. We'd rather spend longer on the survey than hand over an uncertain answer.

George

That's really useful, Dave. So the short answer for any homeowner sitting with a damp patch right now is: don't assume, get a proper survey done first, because the pipe type genuinely changes what happens next.

Dave

That's it. Identifying the pipe type and the leak location before any work starts saves disruption and avoids the cost of repairing the wrong thing. The survey pays for itself in that respect.

George

Dave, thanks so much for breaking that down. If you've got a damp patch you can't explain, ADI Leak Detection are one of the UK's most trusted names in residential water leak detection, and their engineers carry the full range of equipment we've talked about today. We'll be back with another question very soon.

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.