Leak Detection in Heating Systems

A leak in the heating circuit is one of the hardest problems to detect: the pipes are hidden inside walls, false ceilings or under the floor. At Telefuga we use infrared thermography and tracer gas to locate the leak point without destructive works.

Is your boiler constantly losing pressure?

If you need to top up your boiler's pressure every few days, there is probably a leak in the heating circuit. Do not wait for the water to damage the structure or for the boiler to fail from running on low water.

Signs of a leak in the heating system

• Pressure drop in the boiler: you need to top up water frequently.
• Damp stains on walls or floors: near radiators or concealed pipework.
• Radiators that do not heat: one or more radiators stop working.
• High gas bill: the boiler works harder than normal to compensate.

How it is located

With the system cold we pressurise the circuit to verify the pressure drop; in installations with several circuits, each one is tested separately.

Thermography with the system hot shows the route of the pipes as warm lines; a leak interrupts that line or creates a diffuse patch. Thermography sees temperatures, not the leak itself: it needs real thermal contrast, loses effectiveness in deep pipes and produces false positives (thermal bridges, beams, uninsulated areas), so it is used to orientate, not to mark the point.

The point is located with tracer gas: underfloor heating pipe is plastic and often does not sound, so the circuit is emptied, charged with a mixture of tracing gases and its escape is traced at the surface. The geophone helps to narrow down the location on metal radiator pipework when the circuit is under pressure.

Once located, the floor or wall is opened only in the located area, the section is repaired or replaced, and water-tightness is verified before closing up.

Typical leaks in underfloor heating

Underfloor heating uses cross-linked polyethylene (PEX) or polybutylene pipes beneath a layer of mortar. Typical leaks are accidental punctures (a wall plug or a screw over the route), a joint defect in the manifold that leaks slowly over years, and deterioration of components caused by untreated water.

A patch of floor that is clearly warmer than the rest, outside the normal pattern, can indicate hot water accumulating outside the pipe.

Systems we work on

• Hot water radiators
• Closed boiler circuits
• Concealed wall pipework
• Fan coil systems
• Boilers and manifolds
• Radiator valves and lockshield valves