Central Heating Leak Detection in Burpham

Symptoms

At a property in GU4, the central heating system was losing pressure within the hour of being reset at the boiler, which is located in the utility room. The repeated pressure drops pointed clearly to an active leak somewhere within the heating circuit, but the source was not immediately obvious given the mix of flooring types across the property — suspended floors in most rooms and a solid concrete floor with tiles in the kitchen and dining area.

The clearest visible indicator was water appearing beneath and around the TV cabinet in the living room, rising up through gaps in the floor and accumulating along the skirting boards. This kind of water ingress beneath a suspended floor, combined with rapid pressure loss, called for a structured central heating leak detection approach to accurately identify the source before any intrusive work began.

Because underfloor heating runs through the concrete section of the property, there was a meaningful risk the leak could be buried within the slab — a scenario that would have significant implications for both investigation and repair.

Methods Used

The investigation began with thermal imaging to map the heating pipework across the property. This revealed a heat patch in the same area of the living room where water had been seen surfacing — a strong directional indicator before any floor was touched.

The acoustic microphone was then deployed over that area and picked up leak noise clearly, corroborating the thermal finding. Damp meter readings around the same zone were also elevated, and water was visibly present rather than just registering as a reading.

With three independent methods pointing to the same location, the decision was made to lift floor tiles in that area. This is standard practice in central heating leak detection when non-invasive tools have already narrowed the search to a defined zone.

As tiles were removed, water was found trapped beneath. Further exposure of the concrete revealed that the pipework was laid very shallow.

The leak source was then identified: a push-fit coupler where the pipe had slowly backed out of the connection, likely due to ground movement over time.

Investigation Process

1. 1
   Boiler pressure loss confirmed

   The boiler in the utility room was observed to be dropping pressure within the hour, confirming an active leak within the central heating circuit.

2. 2
   Thermal imaging of pipework

   The thermal imaging camera was used to map all heating pipework throughout the property, identifying a heat patch beneath the living room floor in the area where water had been surfacing.

3. 3
   Acoustic detection

   The acoustic microphone was applied over the same area and picked up clear leak noise, providing a second confirmation of the leak location.

4. 4
   Damp meter readings taken

   Damp meter readings around the identified zone were elevated, and water was visibly present — not just registering as a reading.

5. 5
   Floor tiles lifted

   Tiles were removed in the targeted area, revealing water trapped beneath the surface and confirming the investigation had pinpointed the correct location.

6. 6
   Concrete exposed and pipework uncovered

   The concrete floor was opened up to expose the heating pipework, which was found to be laid at a very shallow depth.

7. 7
   Leak source identified

   A push-fit coupler was found where the pipe had slowly backed out of the connection, most likely due to movement in the structure over time — the source of the pressure loss and water ingress.

8. 8
   Repair carried out

   A section of pipe was cut at the failed coupler and replaced using crimped fittings on the plastic pipework to form a secure, permanent connection.

9. 9
   System recommissioned

   The boiler was topped up and inhibitor added to the system. Pressure was monitored on site with no further loss recorded, and everything was confirmed working before the engineer left.

Result & Outcome

The leak was located beneath the living room floor at a push-fit coupler in the plastic underfloor heating pipework. The pipe had gradually worked its way out of the fitting — likely driven by structural movement — allowing pressurised water to escape steadily into the void beneath the floor, eventually surfacing visibly at the TV cabinet and along the skirting boards. The fact that the pipework was laid at a very shallow depth meant the repair was accessible once the tiles and a section of concrete were removed.

The repair was completed on site using crimped fittings, which provide a mechanically secure joint on plastic pipework and remove the risk of the same connection failure recurring. The boiler was refilled with inhibitor added, and pressure was monitored with no further loss — the system was fully functional before the engineer left. This is the expected outcome in central heating leak detection work where non-invasive methods accurately direct the investigation before any opening up begins, keeping the scope of intrusive work to a minimum.

Given the volume of water that had accumulated beneath the floor and around the skirting boards, a drying-out programme for the affected area is strongly recommended before any reinstatement of flooring takes place.