Central Heating Leak Detection in Hertford

Symptoms

With no external signs of a leak and the system still losing pressure, central heating leak detection was required to establish whether a second leak point existed elsewhere in the property. The central heating had been losing pressure consistently enough to suggest an active, ongoing leak rather than a residual issue from the earlier repair.

Methods Used

The system was drained and cleared with a compressor before tracer gas was introduced to the pipework and drawn out via the external drain cock. Walking the known pipe routes on the ground floor with a gas analyser, the only area of escaping gas was around the left-hand radiator connection in the hallway.

A three-millimetre pilot hole drilled into the laminate at the location identified by the earlier methods immediately produced a sharp rise in gas concentration at the analyser, confirming the leak was directly below. This thorough approach to central heating leak detection — using thermal imaging, moisture metering, acoustic testing, and tracer gas in sequence — meant every method pointed to the same point before any flooring was lifted.

Investigation Process

1. 1
   Thermal imaging with heating live

   On arrival the central heating was running, so a thermal imaging camera was used immediately to locate pipe routes beneath the hallway floor and flag a thermal hotspot approximately 12 inches from the left-hand side of the hallway radiator. This area was marked with masking tape.

2. 2
   Moisture meter survey

   All areas identified by the thermal camera were checked with a moisture meter. The hallway hotspot returned a reading of 999, while readings six inches either side were dry, confirming localised moisture at the same point.

3. 3
   Acoustic testing

   Acoustic equipment was used across the marked areas and detected a sound in the floor consistent with an active leak, at the same location identified by both the camera and the moisture meter.

4. 4
   System drained and tracer gas introduced

   The central heating system was drained, then cleared with an air compressor to remove residual water from the pipework. Tracer gas was introduced and drawn through the external drain cock before the ground floor pipe routes were walked with a gas analyser.

5. 5
   Tracer gas escape confirmed at hallway radiator

   The only area of escaping gas detected by the analyser was around the left-hand radiator connection in the hallway. A three-millimetre pilot hole was drilled into the laminate at the target location, after which gas concentration at the analyser rose sharply, confirming the leak was directly below.

6. 6
   Flooring removed and leak located

   With customer consent, a small section of laminate was cut up, revealing parquet flooring beneath with a very high moisture reading. The parquet was removed and, with the compressor re-pressurising the pipework, air could be heard escaping in the floor. A lateral fracture on a pulled bend in the central heating pipework was identified as the source.

7. 7
   Pipe section replaced

   The fractured section of pipe was removed and replaced with a new length of copper tube and fittings, soldered into position using solder and flux.

8. 8
   Pressure test and system reinstatement

   The repaired system was pressure tested at 1.8 bar for 45 minutes with no measurable pressure loss recorded. The system was then refilled, inhibitor chemical added, vented, and heat tested — heat was achieved at all radiators and hot water operation was confirmed satisfactory.

Result & Outcome

On completion of the repair, the system held 1.8 bar for 45 minutes without any measurable pressure drop, confirming no additional leaks were present. The system was refilled with inhibitor chemical added, vented, and heat tested, with heat confirmed at all radiators and hot water operation found to be satisfactory. The customer's problem of needing to re-pressurise the system multiple times a day has been resolved.