How to find a slow leak in a central heating system
Is your boiler constantly losing pressure? Are you worried about how to find a concealed slow leak in central heating system pipes? Don’t worry! Our experts use a range of non-invasive leak detection techniques that reliably help to locate slow leaks while causing no damage to your home – even if there are no visible signs of damp.
In this video, we show you the basic checks our Gas Safe engineers carry out before starting a trace and access investigation. The methodical approach they follow means they can find a slow leak in a central heating system quickly without exposing pipes beneath floors or behind walls.
Video Transcript
Leak detection is one of the specialist services we provide. Our experts are able to find concealed leaks and sources of water ingress anywhere in a property.
In this video we’ll show you how we find a leak in a central heating system, even when there are no visible signs of one. We’ll show some of the non-invasive techniques used as part of the methodical “trace and access” approach that’s favoured by insurance companies.
In this example, a homeowner suspects a water leak in their central heating system. The boiler keeps losing pressure and needs topping up every few days. Sending Gas Safe registered tradespeople to investigate these types of leaks means they’re qualified to work safely on gas powered heating systems. When they find a leak, the repairs can begin straight away.
Pressure Testing
Our tradesman first checked to see whether or not the ongoing drop in pressure was caused by a fault with the boiler. A damaged expansion vessel or pressure release valve are common reasons for a central heating system to lose pressure without there being a leak. In this case, a drop in water pressure was confirmed but there wasn’t a problem with the boiler. The underfloor heating system was isolated and a second pressure test was done. Another drop in pressure indicated a leak in the radiator system rather than the underfloor heating.
Visual Checks
A visual assessment of the exposed parts of the central heating system was carried out to check for leaks. With all radiators, valves and pipework appearing in good condition, the next step in the investigation was thermal imaging.
Thermal Imaging
A thermal image camera is a completely non-invasive technique that gives surface temperature readings quickly and without needing to insert probes. Readings can direct attention quickly to possible evidence of a leak. In this case the camera was used help identify where pipework runs beneath the floor.
Tracer Gas
A tracer gas test was carried out to locate the leak. The central heating system was drained and filled with an inert gas mix. A probe detects the presence of tiny amounts of this gas. The gas is much lighter than air and rises quickly from where it escapes. It can penetrate different floor coverings including wood, tile, vinyl and carpet. It can even penetrate concrete slabs.
The gas is non-harmful, odourless and doesn’t leave any residue, so it’s safe to use in drinking water supply pipes as well a central heating system and drainage pipes. Eventually the gas was detected escaping from beneath a hardwood floor.
Repair & Reinstatement Service
On this occasion, the homeowner chose to have the repair work done after talking with her insurance company. The repair and reinstatement work would involve exposing the leak by removing a section of hardwood floor and a cupboard. Our tradesman provided a scope of work and fixed price while still on site. This accompanied the leak detection report. An Aspect gas engineer and joiner were scheduled to carry the work once the insurance company had given the go ahead.
If you’re trying to find a leak in a central heating system, the trace and access approach shown here can save time and money. Thanks for watching. Check out our other videos in this “how to find a water leak” series. Don’t forget to subscribe to our YouTube channel to keep up to date with more maintenance advice.