Water through the tiles, a warm patch, boiler losing pressure? We find the leaking pipe and open only that spot.
Pick the closest match for a full guide to how that kind of leak is found.
Underfloor heating Loops in screed fed from a manifold. Pressure dropping, warm or damp patches.
Concrete or screed Pipes buried in a solid floor. Damp flooring, salts, a meter that keeps turning.
Floorboards Pipes in the void under timber. Ceiling stains below, lifting boards, musty smells.
Heating losing pressure The boiler keeps needing topping up and nothing is visible. Start here.
Is there a leak, and which pipe is it on?
The engineer isolates one part of the system at a time, such as a single underfloor heating circuit at the manifold, the hot supply or the cold supply, and pressurises it with water or air.
Where do the pipes run, and where is warm water spreading?
A thermal camera shows surface temperature as colour. Warm pipes in a floor show as lines, and warm water escaping shows as a patch that spreads away from the line.
Can we hear water, or air, escaping at one spot?
Water escaping from a pressurised pipe makes a noise. A ground microphone on the floor surface amplifies it, and the engineer moves across the floor until the sound is loudest.
Where is gas coming up through the floor?
The pipe is drained and filled with a safe mix of hydrogen and nitrogen. Hydrogen is a very small molecule, so it escapes through the same hole as the water and works its way up through screed, concrete and joints.
Where is the floor wet, and how far has it spread?
A moisture meter measures how wet a surface is, without damaging it. Readings are taken across the floor, skirting and walls to map where the water has gone.
Water was rising through gaps in the living room floor. Three methods agreed on one spot, a few tiles were lifted, and a push-fit coupler had slid off the plastic heating pipe.
Leak found; joint remade with crimped fittings; pressure held
Acoustics and tracer gas were both misled by the way the pipes were laid. Warm water and a thermal camera showed the real pipe route and a faint mark at the leak.
Leak located; repaired by the site plumbers
Another engineer had confirmed the system was leaking but not where. Thermal, moisture, acoustic and tracer gas readings agreed on the living room before a single board was lifted.
Pinhole found; section replaced in copper
It looked like an underfloor heating leak. Isolation testing put it on the water softener bypass instead, and thermal, acoustic, tracer gas and moisture readings all pointed to one threshold.
Leak found at the kitchen threshold; copper pipe replaced; retest clear
Excellent 4.7 out of 5 from 1,618 reviews of ADI Leak Detection on Trustpilot (opens in a new tab)Checked 22 September 2026
“I had a central heating leak that was driving me nuts. Two plumbers couldn't find and suggested I pull my LVT flooring up. I called ADI and am so glad I did. From my initial phone call and speaking to Caroline in the office to the final fix was efficient, pain free and effortless. Brett, the engineer arrived on time and set about with his array of instruments and tracked and confirmed the leak.”
“Robert arrived promptly, he was very courteous and ran through everything with us. Then using the specialised equipment, he located the leak under the concrete quickly. He repaired the pipework, performed a thorough check and maintenance of the rest of the pipes in the house. Robert was a very clean and tidy tradesman. We throughly recommend ADI Leak Detection.”
“I cannot praise this company enough. From my initial enquiry with Christian who was professional and talked me through the procedure for finding my hidden leak and gave me sound advice. To Frank who was the most hard working polite engineer who successfully solved my problem and made minimal damage to my kitchen floor when he pin pointed the leak underneath my stone tiles. I would thoroughly them to recommend to anyone.”
“Excellent service from start to finish. Caroline was very helpful and informative in the initial call, explaining fully how it worked and what the steps were and then we were lucky enough to have Kristof arrive on the day. He was very thorough, identified where the leak was (under the screed in the living room) and then carried out the repair with minimal mess or disruption.”
“We had what appeared to be an underfloor heating system leak. Frank arrived and within an hour had pinpointed that the water was in fact coming from a leaking toilet pipe and then travelling under the floor. He very efficiently repaired the problem and cleaned everything up. Very pleased with his work!”
“ADI Leak Detection came out to find the leak in my under floor heating, the technicians name was Gabor, the leak in our under floor heating really was challenging to find, Gabor is very experienced and was the right person for the job, after a lot of different equipment and brain power, he located the area to dig, found and repaired the leak, he is very good at his job, I would thoroughly recommend Gabor and ADI Leak Detection.”
If your home insurance includes trace and access cover, it normally pays for finding the leak and opening the floor to reach it.
Check your policy or ring your insurer before booking. You get a written report of what was tested and where the leak is, to send to your insurer or loss adjuster.
Leaks and insurance explainedThe usual signs are a warm patch on a floor that should be cold, damp or lifting flooring, water at the skirting with no leak above it, a musty smell, a boiler that keeps losing pressure, a water meter that moves when every tap is off, or a hissing sound with nothing running.
One sign on its own can have other causes, such as condensation, a shower seal or a leak in the wall. A survey tests the pipes rather than guessing from the stain. See signs of a leak under the floor.
The finding is done from the surface: pressure testing, thermal imaging, acoustic listening, tracer gas and moisture readings. None of them needs the floor up.
To repair the pipe, the floor above the leak has to be opened, but only there. On our cases that has meant a few tiles, one strip of floorboards or a small patch of screed rather than a whole room.
An engineer is booked for the day. Some leaks are found in a couple of hours; complex systems with many circuits take longer. Reviews on this site mention both.
Pressure test gauges and isolation valves, thermal imaging cameras, acoustic ground microphones, hydrogen tracer gas and sensors, moisture meters, endoscope cameras, flow meters and leak dye. Each answers a different question, and the engineer uses them to check each other. See the equipment.
Someone needs to let the engineer in and be around to agree before any floor is opened. It helps to clear furniture from the rooms involved, know where the stopcock, boiler and underfloor heating manifold are, and have any drawings or photos from when the floor was laid.
Possibly, but check the manifold first. Look for drips or white crust at the valves, actuators and connections, and at the pressure relief valve outlet. If the manifold is dry, the leak may be in a circuit, on a radiator pipe, or at the boiler.
Each underfloor circuit can be isolated at the manifold and pressure tested on its own, which tells you which loop is leaking before anyone searches the floor. Underfloor heating leaks.
Often, yes. The engineers are plumbers and many of our cases were repaired on the day. Sometimes a repair has to wait, for example when the pipe needs a different fitting, the floor needs specialist lifting, or another trade has to be involved.
The engineer makes the opened area safe and tidy and, where it is a small patch, can make it good. Wet screed and subfloors usually need to dry before the final floor finish goes back, and tiles or wood flooring are normally reinstated by a flooring fitter. Ask on the phone what is included for your floor.
Underfloor Leak Detection is a specialist service from ADI Leak Detection, started in 2011, with 25+ engineers across England, Scotland and Wales.
The engineers are plumbers as well as leak investigators, so a leak can often be repaired on the same visit. ADI holds £5 million public liability insurance and is a member of CIPHE, WIAPS, WaterSafe and SPATA.
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