Central Heating Leak Detection London
Boiler pressure keeps dropping? Radiators not heating properly? Our thermal imaging and acoustic equipment finds hidden central heating leaks in pipes, radiators, and valves without ripping up your home. Fast diagnosis, same-day repairs.
07456 975436Central heating leak detection in London costs between £150 and £350. If your boiler pressure keeps dropping, the most likely cause is a leak in the pipework, radiators, or valves. Our thermal imaging and acoustic equipment finds the source without damage. Many leaks are repaired on the same visit.
Why Your Central Heating Is Losing Pressure
A sealed central heating system should hold its pressure between 1 and 1.5 bar without needing to be topped up. If you are regularly adding water through the filling loop, something is wrong. In most cases, the cause is a leak somewhere in the system that is allowing water to escape faster than you might expect from even a tiny opening.
The challenge is that central heating leaks are often invisible. A pinhole leak in a pipe running under the floor might only lose a few drops per hour, but over days and weeks that adds up to significant water loss and pressure drop. The water may be absorbed by the screed, evaporate from warm surfaces, or drain away beneath the floor without ever showing on the surface.
At Leak Detect London, we use thermal imaging cameras and acoustic detection equipment to find these hidden leaks quickly and accurately. The heated water in your system creates strong thermal signatures that our cameras detect through floors and walls, while our acoustic equipment hears the sound of pressurised water escaping at the leak point.
Common Types of Central Heating Leaks
Radiator Valve Leaks
Thermostatic radiator valves and lockshield valves develop leaks over time as the internal seals and spindle packing wear. These leaks are often slow enough that the water evaporates from the warm valve body before forming a visible drip, making them difficult to spot. Our thermal cameras detect the cooled area around a weeping valve instantly.
Pipe Joint Failures
Soldered copper joints, compression fittings, and push-fit connections can all fail with age. The most problematic are joints hidden under floors, behind kitchen units, or inside wall cavities where the leak is completely invisible. We trace the full pipe route using thermal imaging and check every joint for signs of failure.
Pinhole Corrosion in Pipes
Internal corrosion causes tiny holes in copper pipes, particularly in systems where the water has not been treated with inhibitor. These pinholes are barely visible to the eye but leak enough water to drop your system pressure steadily. Older London properties with original copper pipework are particularly susceptible to this type of failure.
Under-Floor Pipe Leaks
In many London properties, particularly those built between the 1950s and 1980s, heating pipes run through concrete floor slabs. These pipes develop leaks at joints, bends, and corrosion points. Because the pipes are buried in concrete, the leak is completely hidden until the water finds its way to the surface, which can take months.
Our Pressure Loss Diagnosis Process
When you call us about a central heating pressure loss, our engineer follows a systematic process to identify the cause. First, we check the boiler itself for leaks at the heat exchanger, pressure relief valve, and pump connections. Many pressure loss issues originate at the boiler and can be resolved quickly.
If the boiler is sound, we test the expansion vessel to ensure it is holding its pre-charge and functioning correctly. A failed expansion vessel can mimic the symptoms of a system leak. We also check the pressure relief valve discharge pipe for signs of water, which would indicate the valve is opening and releasing water from the system.
Once we have ruled out boiler and vessel issues, we isolate sections of the system and perform pressure drop tests to narrow down which circuit contains the leak. With the leaking circuit identified, we deploy thermal imaging and acoustic equipment to pinpoint the exact location. This methodical approach saves time and ensures we find the right leak first time.
For systems with underfloor heating zones, we can isolate each zone at the manifold and test individually. This is essential for properties that have both radiator circuits and underfloor heating running from the same boiler.
System Testing and Verification
After locating and repairing the leak, we carry out a full pressure test on the system to confirm it is now watertight. We pressurise the system to 1.5 times the working pressure and monitor it for a minimum of 30 minutes. This test confirms the repair has been successful and that there are no secondary leaks elsewhere in the system.
We also check the system inhibitor levels and top up if needed. Correct water treatment is essential for preventing future corrosion and protecting the boiler, radiators, and pipework. If the system water is heavily contaminated with sludge or corrosion debris, we may recommend a powerflush to clean the system and prevent further problems. Our full water leak detection service covers all aspects of system integrity.
Central Heating Leaks in London Properties
Different types of London property have different heating system configurations and therefore different leak risk profiles. Victorian and Edwardian houses often have been retrofitted with central heating using copper pipes run through floor voids and behind plaster. These installations may be 30 to 50 years old and the pipework is reaching the end of its life.
Post-war flats and maisonettes frequently have heating pipes buried in concrete floor slabs, which are notoriously difficult to access when they develop leaks. Modern new-builds use plastic pipes with push-fit fittings, which are less prone to corrosion but can develop leaks at joints if not installed correctly.
Whatever your property type, our detection equipment and methods are designed to handle every scenario. We work across all London boroughs and carry the full range of thermal, acoustic, and tracer gas equipment to every job.
Central Heating Leak Detection Questions
Why does my central heating keep losing pressure?
How do you find a central heating leak that is hidden?
How much does central heating leak detection cost in London?
Can you detect a leak in pipes running under a concrete floor?
Should I turn off the heating if I suspect a leak?
Boiler Pressure Dropping?
Stop topping up and start finding the cause. Call us for a same-day central heating leak investigation across London.
07456 975436Full System Diagnosis
We check the boiler, expansion vessel, pressure relief valve, and entire pipe system before deploying detection equipment. Methodical diagnosis means we find the real cause first time.