Central Heating Leak Detection in Bordon

Symptoms

The heating system at a property in GU35 had stopped working entirely. The boiler pressure had dropped to 0 bar, there was no heat being produced, and no visible water was present anywhere in the property.

With no obvious signs of a leak on the surface and no damage found during the initial inspection, this was a concealed loss of pressure within the heating circuit.

Situations like this — where the system has lost pressure but left no visible trace — require methodical central heating leak detection to establish where the water is going. The absence of surface moisture or physical damage made it clear that if a leak existed, it was almost certainly underground or otherwise hidden beneath the building fabric.

Methods Used

The investigation began with acoustic listening, which picked up a clear noise at one radiator in the hallway — this gave an early focus point for the rest of the work. Thermal imaging was attempted but returned no useful results.

A damp meter was also used, but the readings were not conclusive. Tracer gas was then introduced to the system and produced a strong reading near the hallway radiator, confirming that area as the leak location.

This combination of methods is standard practice in central heating leak detection where the leak is concealed beneath solid floors. With acoustic and gas evidence both pointing to the hallway, the decision was made to lift the carpet and open the concrete floor.

A 120mm channel was cut into the concrete to expose the pipework beneath, where two copper heating pipes were found running under the floor.

Investigation Process

1. 1
   Initial inspection

   The engineer arrived and assessed the system. The boiler was at 0 bar, there was no heating, and no visible water or damage was found anywhere in the property.

2. 2
   Acoustic listening

   A listening stick was used throughout the property. A clear noise was detected at the radiator in the hallway, identifying it as the primary area of interest.

3. 3
   Thermal imaging attempted

   A thermal camera was used in the hallway area but returned no results, and could not confirm the leak location.

4. 4
   Damp meter used

   A damp meter was applied to the floor and surrounding area, but the readings were not good enough to pinpoint the leak.

5. 5
   Tracer gas introduced

   Tracer gas was added to the heating circuit. A strong reading was detected near the hallway radiator, confirming it as the leak area.

6. 6
   Carpet lifted and floor opened

   The carpet was removed and a hole was made in the concrete floor, revealing two copper heating pipes beneath. The leak could not be located at this initial point.

7. 7
   120mm channel cut in concrete

   A 120mm channel was cut into the concrete floor to expose more of the pipework. The leak was eventually found in a section of copper pipe in very poor condition.

8. 8
   Pipe replaced

   Approximately 1 metre of copper pipe was replaced using two straight 15mm copper connectors, 15mm copper pipe, and a 15mm push-fit elbow.

9. 9
   Pressure test carried out

   The repaired section was pressure tested and returned good results, confirming the integrity of the repair.

10. 10
    Area made safe

    The excavated area was backfilled and cleaned. Concrete reinstatement was not carried out, as remedial works are outside the scope of the service.

Result & Outcome

The leak was located beneath the hallway floor, in a section of copper heating pipe in very poor condition. Tracer gas provided the definitive confirmation after acoustic listening had narrowed the area and thermal imaging and damp metering had both proved inconclusive. A 120mm channel had to be cut into the concrete before the deteriorated pipe section could be exposed and assessed.

Approximately 1 metre of copper pipe was replaced using two straight 15mm connectors, 15mm copper pipe, and a 15mm push-fit elbow. The subsequent pressure test returned good results, confirming the circuit was sound. For any central heating leak detection job where the pipework runs beneath a solid concrete floor, physical excavation is often unavoidable once non-invasive methods have done their work in narrowing the location.

The customer was advised that concrete reinstatement is not part of the service. The area was backfilled, cleaned, and left safe, with the heating system restored to working pressure.