Hot Water System Leak Detection in Poplar

Symptoms

A property in E15 presented with visible leak damage spread across the kitchen area and an adjacent bathroom. Walls and flooring in both rooms showed signs of significant moisture ingress, and there was an audible noise on the mains supply line feeding the combi boiler — both indicators that a leak had been active for some time beneath the surface.

The pattern of damage suggested the source was concealed within the building fabric rather than at any visible fitting or joint. With water appearing to be moving through the system even when no hot water was in use, a structured hot water leak detection investigation was needed to identify the precise point of failure before any remedial drying or reinstatement work could begin.

Trace and access work was required to locate the leak and expose it for repair, with the investigation covered under the property's buildings insurance policy.

Methods Used

The investigation began with a visual inspection of all affected areas, followed by damp meter readings across the kitchen and bathroom to map the full extent of saturation. With maximum readings recorded throughout both rooms, attention turned to tracing the active leak on the hot water circuit.

Isolating the mains supply into the combi boiler and observing that the noise on the pipe stopped confirmed the leak was on the hot supply rather than the cold feed or a drain connection.

Thermal imaging was then used to scan the hot water run beneath the floor, which identified a thermal irregularity under the sink unit and behind the dishwasher position. This gave a precise target for excavation.

As a hot water leak detection method, thermal imaging is particularly effective in screed floors where heat from a leaking pipe creates a detectable signature that damp meter readings alone cannot pinpoint. The dishwasher was removed, the screed excavated, and the failed pipe section was exposed, repaired, and pressure tested before the job was closed.

Investigation Process

1. 1
   Visual inspection of affected areas

   On arrival, all leak-affected areas were inspected visually. Severe leak damage was confirmed to walls and flooring in the kitchen and the adjacent bathroom.

2. 2
   Damp meter survey

   Damp meter testing was carried out across the kitchen and bathroom. Maximum readings were recorded on the flooring and walls throughout both rooms.

3. 3
   Sectional isolation of mains supply

   The mains supply into the combi boiler was isolated. The audible noise on the pipework ceased immediately, confirming the leak was on the hot supply circuit.

4. 4
   Thermal imaging of hot water run

   A thermal scan was carried out along the hot water run beneath the kitchen floor. A thermal irregularity was identified under the sink unit and behind the dishwasher position.

5. 5
   Removal of dishwasher and excavation of screed

   The dishwasher was removed to allow access. Screed above the thermal irregularity was excavated to expose the pipework below.

6. 6
   Failed pipe located

   Pooled and flowing water was found below a damp proof membrane sitting above all pipework. A 15mm copper hot supply pipe was found with a perforation on its underside.

7. 7
   Repair and pressure test

   The failed section of 15mm copper hot supply was renewed. The repaired section was tested at 4.0 bar of compressed air over one hour with no pressure drop recorded.

8. 8
   Customer advised on next steps

   The customer was advised to send the engineer's report to their insurers to arrange professional drying of all affected areas and full remedial reinstatement, all covered under the trace and access clause of their buildings insurance policy.

Result & Outcome

The leak was found in the screed beneath the kitchen floor, under the sink unit and behind the dishwasher position. A 15mm copper hot supply pipe had failed with a perforation on its underside — a type of failure that directs water downward into the screed rather than upward where it would be immediately visible, explaining the extent of concealed damage across the kitchen and bathroom before the leak was detected.

The failed section was cut out and renewed. Pressure testing at 4.0 bar over one hour with no recorded drop confirmed the repair was complete and sound. For a hot water leak detection job of this type — a buried pipe under screed with no visible access point — thermal imaging was the critical tool that avoided unnecessary widespread excavation and directed work precisely to the source.

With the leak repaired and the circuit proven watertight, the customer has a clear documented report to submit to their insurer. All professional drying and reinstatement of the kitchen and bathroom surfaces are to be arranged through the buildings insurance policy under the trace and access provision.