Central Heating Leak Detection in Cricklade

Symptoms

Central heating leak detection was clearly needed, but pinpointing the source was not straightforward. The system included both underfloor heating circuits and a radiator circuit, meaning the leak could have been anywhere across a relatively complex layout.

Systematic isolation was required before any trace work could begin.

Methods Used

Endoscope investigations were carried out at low level in the wall adjacent to the hob, where a leaking redundant heating pipe was identified. A section of wall was removed to allow further endoscope work, which indicated the actual leak point was behind the hob unit itself.

Following agreement with the customer, the hob unit area was exposed to access the pipe. This approach — methodical isolation followed by tracer gas and camera work — is standard practice in central heating leak detection where the leak cannot be located by pressure testing alone.

Investigation Process

1. 1
   System refilled and pressure loss confirmed

   The heating system was refilled to 1 bar. Pressure dropped to zero within ten minutes, confirming an active leak.

2. 2
   Underfloor circuit #1 isolated and tested

   The first underfloor heating circuit was isolated and a separate pressure test carried out. The result was the same — pressure dropped to zero within ten minutes.

3. 3
   Underfloor circuit #2 isolated and tested

   The second underfloor heating circuit was isolated and pressure tested with the same outcome, eliminating both underfloor circuits as the source of the leak.

4. 4
   Radiator circuit drained and tracer gas applied

   With both underfloor circuits ruled out, the radiator circuit was drained and tracer gas investigations were carried out. A high gas reading was detected in the kitchen and a bubbling noise could be heard.

5. 5
   Endoscope investigation in kitchen wall

   An endoscope camera was used at low level in the wall adjacent to the hob. A leaking redundant heating pipe was identified within the wall void.

6. 6
   Wall opened and further endoscope work carried out

   A section of the wall was cut away to allow further endoscope investigation, which indicated the actual leak point was behind the hob unit.

7. 7
   Area behind hob exposed

   Following discussion with the customer, further exposure was agreed to access the leaking 15mm copper pipe located behind the hob unit.

8. 8
   Leaking pipe identified and cause established

   The 15mm copper pipe was found to be in contact with a sharp stone, which had been cutting into the pipe wall. The stone was removed.

9. 9
   Pipe cut and capped

   The leaking redundant section of 15mm copper pipe was cut short and capped off to seal the circuit.

10. 10
    Pressure test passed and system refilled

    A pressure test at 2 bar held for 20 minutes with no drop, confirming the repair. The heating system was refilled and six radiators were vented.

Result & Outcome

For central heating leak detection jobs of this type — where the system spans multiple circuits and the leak is concealed within a wall void — systematic isolation and tracer gas work are essential to avoid unnecessary exposure. In this case, the combination of sectional isolation, tracer gas, and endoscope camera work meant the exact leak point was confirmed before any significant opening up was agreed with the customer.