Underfloor Heating Leak Detection in Nottingham

Symptoms

A property in NG17 that was under construction had a confirmed leak on the underfloor heating system. The pipework had been installed as separate runs connected to a manifold, and the concrete screed had been laid over the top, but the system had not yet been commissioned and no boiler was connected.

Engineers were directed to the middle of the room as the suspected location of the leak.

Methods Used

The remaining runs on the manifold were isolated by the onsite plumber to allow focused testing on the affected circuit. A pressure test confirmed the leak, and acoustic equipment was deployed first.

Although the acoustics detected noise consistent with a leak, the ring configuration of the underfloor heating pipe runs caused the sound to travel along the pipework, preventing a precise location from being established beyond the general system area. Tracer gas was introduced next and readings were obtained quickly near the window, but gas was found to be escaping from the sides of the room rather than the actual leak point.

A section of screed was exposed in the corner, which revealed the gas was migrating along the pipe runs through a narrow channel formed within the concrete — a known limitation when using tracer gas in screed-encased systems.

Investigation Process

1. 1
   Remaining runs isolated

   The onsite plumber isolated the other runs on the manifold, leaving only the affected circuit under test.

2. 2
   Pressure test carried out

   A pressure test was performed and confirmed a leak was present on the circuit.

3. 3
   Acoustic equipment deployed

   Acoustics detected leak noise but the ring configuration of the underfloor heating runs caused the sound to travel along the pipework, preventing the fault from being narrowed down beyond the general area.

4. 4
   Tracer gas introduced

   Gas readings were obtained quickly near the window area, but gas was found escaping from the sides of the room rather than the leak location itself.

5. 5
   Screed exposed to investigate gas migration

   A section of concrete screed was removed in the corner, revealing that the tracer gas was travelling along the pipe runs through a small channel formed within the screed.

6. 6
   Hot water run through pipes for thermal trace

   With no boiler on site, hot water was manually run through the pipes to create a weak thermal trace; the cold screed floor provided sufficient contrast for the camera to detect the warm pipework.

7. 7
   Pipe run locations confirmed by thermal imaging

   Thermal imaging showed the pipework was running along the left side of the room, not through the middle as engineers had been told, explaining the difficulty in the acoustic phase.

8. 8
   Thermal anomaly detected and leak exposed

   The thermal camera identified a faint anomaly on the middle of the left side of the floor; onsite plumbers exposed that area and the leak was confirmed on the pipework.

Result & Outcome

The leak was located on the underfloor heating pipework on the left side of the room, identified by a faint thermal anomaly detected after hot water was run through the pipes. The onsite plumbers exposed the screed at that point and confirmed the fault. The leak was then repaired by the plumbers on site.