Central Heating Leak Detection in Folkestone

Symptoms

A property in CT20 — a semi-detached block of apartments — developed visible water damage to the ceiling and wall of Apartment 5. The affected area sat directly below Apartment 7, pointing to a leak originating from the upper flat.

On arrival, the boiler in Apartment 7 was found to be running at very low pressure, which was consistent with a loss of water from the central heating system.

The damage in Apartment 5 was tracking downward through the structure, suggesting that water had been escaping over a period of time. With the source unconfirmed, central heating leak detection was required to establish precisely where the system was losing pressure and whether the leak was active within the pipework serving Apartment 7.

The complication here was the presence of old, disused pipework concealed behind the walls — pipework that was no longer part of the active system but still capable of holding and releasing residual water. This made a systematic, equipment-led investigation essential before any remedial work could be scoped.

Methods Used

The investigation began with the boiler repressurised and the heating system activated, while a damp meter was used in the affected areas of Apartment 5 to establish the extent and direction of moisture penetration. Thermal imaging was then applied to the heating pipework within Apartment 7 to check for any anomalies under live operating conditions — none were detected.

With thermal imaging ruling out obvious active faults in the live pipework, the system was isolated and drained to allow tracer gas testing. This is a standard method in central heating leak detection when visual and thermal methods do not identify the source.

A consistent pressure drop was recorded, and tracer gas was detected near the television unit. An endoscope camera was then used to inspect behind the wall in that area, where old disused pipework was identified.

Evidence pointed to a leak from this redundant pipework at low level, concealed behind the units.

Investigation Process

1. 1
   Initial assessment and boiler repressurisation

   On arrival, the boiler in Apartment 7 was found to be at very low pressure. The system was repressurised and the heating activated to allow live testing to begin.

2. 2
   Moisture meter testing in Apartment 5

   Concurrent with the boiler being brought back up to pressure, damp meter readings were taken in Apartment 5. Elevated moisture levels were confirmed, consistent with water damage tracking down to floor level.

3. 3
   Thermal imaging of heating pipework

   Thermal imaging was carried out across the heating pipework within Apartment 7 while the system was live. No thermal anomalies were detected.

4. 4
   System isolation, drain-down and tracer gas testing

   The boiler was isolated and the heating system fully drained. Tracer gas was then introduced, and a consistent pressure drop was recorded during testing.

5. 5
   Tracer gas detection near television unit

   Tracer gas was detected in the area of the television unit, narrowing the leak location to that section of the wall.

6. 6
   Endoscope investigation behind the wall

   An endoscope camera was used to inspect behind the wall at the suspected location, revealing old disused pipework. Evidence indicated a leak from this pipework at low level behind the units.

7. 7
   Access, capping and re-test

   Following discussion with the customer, access was made into the ceiling and the redundant pipes were capped off using two 10mm caps and inserts. A re-test confirmed no further pressure loss.

8. 8
   System refill and boiler recommission

   The heating system was refilled and the boiler was recommissioned, returning the central heating to full working order.

Result & Outcome

The leak was traced to old, disused pipework located behind the wall in Apartment 7, at a low level in the vicinity of the television unit. This pipework was no longer part of the active heating circuit but had been retaining water and leaking, causing the damage that had tracked down into Apartment 5 below.

Once the source was confirmed via tracer gas and endoscope camera, access was made into the ceiling and the redundant pipes were capped off using two 10mm caps and inserts. A re-test of the system confirmed no further pressure drop, and the boiler was recommissioned. For a central heating leak detection job of this type — where the leak originates from concealed, redundant pipework rather than the active circuit — capping the disused section is the appropriate resolution.

The plasterboard ceiling in Apartment 7 will require repair following the access work. With the leak now resolved, the water-damaged areas in Apartment 5 are ready to proceed with drying and reinstatement.