Central Heating Leak Detection

The classic symptom: your combi boiler pressure gauge drops from 1.5 bar to zero over a few days, you top it up, and it drops again. There is no puddle, no damp patch and no obvious culprit, because the leak is under the floor, buried in screed, or hidden in a boxed-in pipe run. Repeatedly topping up is more than an annoyance. Fresh water brings oxygen and minerals into the system that corrode radiators and can shorten the life of your boiler.

Why heating leaks are hard to find

Modern heating systems run pipework under solid floors, through joists and inside walls. A leak of less than a litre a day, enough to drop your boiler pressure overnight, can disperse into the sub-floor without ever showing on the surface. Ripping up floors to look is expensive, disruptive and usually wrong on the first guess.

How we trace them

• System pressure testing. The boiler, radiators and pipe runs are isolated in turn to confirm the loss is genuinely in the pipework and narrow it to one zone.
• Thermal imaging. With the heating running, buried pipe runs glow through the floor covering. A leak shows as a distinctive spreading plume rather than a neat pipe line.
• Hydrogen tracer gas. For drained or stubborn systems, we charge the circuit with a safe trace gas and sweep the floor with a gas-sniffing probe. The gas escapes at the leak and rises straight up through screed, tile and laminate.

Sealed system and boiler pressure checks

Not every pressure drop is a pipework leak. Expansion vessels, pressure relief valves and automatic air vents all lose water invisibly. The relief valve discharges outside, so you may never see it. We check these first, so you do not pay for a floor survey when the fix is a small valve.

Once found, we mark the leak location, provide a written report with thermal evidence for your insurer, and, because we are heating engineers, we can normally carry out the repair and re-commission the system ourselves.