Leak Detection London — Non-Invasive, All Boroughs

Leak Detection in London — Finding Hidden Leaks Without Tearing Up Your Home

A water bill that has jumped for no obvious reason. A patch of damp appearing on a wall or ceiling with no apparent source. A pressure drop across the whole property. These are the signs of a hidden leak, and finding it without the right equipment means guessing and digging. We do not guess.

Your local leak detection specialist from 247 Plumber London uses thermal imaging cameras, acoustic listening equipment and tracer gas systems to pinpoint exactly where a leak is before any surface is opened up. We find the leak. Then we fix it. Minimum disruption to your property.

Signs You Have a Hidden Leak

Unexplained Water Bill Increase

A sudden or gradual increase in your water bill without any obvious change in usage is one of the clearest signs of a hidden leak. Thames Water provides average household usage data and any significant deviation is worth investigating. A leak of one litre per minute would add around fifty to sixty pounds to a monthly water bill and might not produce any visible symptoms inside the property for months if the water is finding its way into the ground outside.

Damp Patches on Walls or Ceilings

A wet patch on a ceiling directly below a bathroom is the most common presentation we see. The patch appears and then perhaps dries out, then appears again after someone uses the bath or shower. This pattern almost always indicates a failed seal around the bath or shower tray rather than a pipe leak. The water is getting under the tray or behind the tiles and tracking across the floor structure before dropping through the ceiling below.

A damp patch on an internal wall that has no bathroom or pipe run above it is more complex. It might be a heating pipe buried in the screed below the floor, a joint in an underground section that has failed, or in older London properties a lead pipe that has corroded through from the inside. These are exactly the situations where our leak detection equipment earns its keep.

Loss of Boiler Pressure

A sealed central heating system that needs topping up repeatedly has a leak somewhere. The leak might be obvious, such as a weeping radiator valve or a dripping compression fitting. If you have checked every visible radiator and pipe joint and they all appear dry, the leak is hidden. It might be in underfloor pipework, in a section of pipe within a wall, or at a joint buried in screed.

Hot Spots on Floors

If you have underfloor heating and one section of floor feels noticeably warmer than the rest, or if a section of floor feels warm when the heating is not on, that warmth might be from a leaking pipe. Thermal imaging cameras show temperature differences on floor surfaces with extraordinary precision and can map the exact route of a buried pipe to identify which section is leaking.

How We Find Hidden Leaks

Thermal Imaging

A thermal imaging camera detects differences in surface temperature that are invisible to the naked eye. Water leaking from a pipe creates a temperature difference in the surrounding material as it evaporates or as it carries heat from a hot pipe. We can scan floors, walls and ceilings and see the leak’s influence on the temperature pattern without touching anything.

Thermal imaging works best when there is a reasonable temperature difference between the leaking water and the surrounding surface. It is most effective on underfloor leaks from heating pipes, on hot water pipe leaks within walls, and on bathroom floor leaks where water is spreading under the tiles. In some cases we combine thermal imaging with acoustic detection for a definitive result.

Acoustic Leak Detection

Every pipe leak makes a sound. The pressure of water escaping from a hole in a pipe creates a hiss or a low frequency noise that travels through the surrounding material. Acoustic listening equipment amplifies this sound and allows us to move along a floor or wall and hear the leak getting louder as we approach it. We can pinpoint a leak to within centimetres in most cases.

Acoustic detection is particularly useful for underground leaks in water supply pipes beneath garden paths, driveways and public footpaths. The sound travels well through concrete, tarmac and soil. We can walk a route above an underground pipe and use the sound to locate the leak without any digging at all until we know exactly where to open up.

Tracer Gas Detection

For the most difficult to locate leaks, we use tracer gas detection. A harmless mixture of hydrogen and nitrogen is introduced into the pipe under test. The gas escapes from the leak point and rises through the surrounding material to the surface. A highly sensitive detector at surface level picks up the gas concentration and shows us exactly where it is escaping. This method works on water mains, drainage systems, underfloor heating circuits and buried heating pipes and is accurate even when the leak is several metres below the surface.

Insurance Reports and Trace and Access Cover

Many home insurance policies include trace and access cover, which pays for the cost of locating a hidden leak and making good the area opened up to access the pipe. The repair of the pipe itself may be covered separately or may be your responsibility depending on the policy. We are experienced in providing the detailed written reports that insurers require, including photographs of the detection process, the identified leak location, the pipe exposed, the repair carried out, and the reinstatement of the surface.

If you are making a trace and access claim, call us before you call a general plumber. Using the right detection methods from the start rather than opening up based on guesswork can be the difference between an insurer paying out and refusing on the grounds that unnecessary damage was caused.

Frequently Asked Questions

How accurate is thermal imaging leak detection?

Very accurate in the right conditions. Thermal imaging detects temperature differences of less than one tenth of a degree Celsius on surfaces. For hot water pipe leaks and underfloor heating leaks it is extremely precise. For cold water leaks in cold ambient conditions, acoustic detection may be more reliable and we often use both together.

Will you have to open up my floors or walls?

Only once we have located the leak precisely. The whole point of our detection equipment is to avoid unnecessary damage. When we do open up, it is at the exact location of the leak, not a speculative area. We make the smallest opening that gives us proper access to carry out the repair.

My boiler keeps losing pressure but I cannot see any leak. What should I do?

Call us. A system that keeps losing pressure has a leak somewhere. We will carry out a systematic pressure test and check all visible joints, radiator valves and connections first. If nothing obvious is found, we move to leak detection equipment to find where the water is going.