A Thermal Imaging Survey is a non-invasive diagnostic procedure used to identify abnormal heat signatures within your electrical system that may indicate a developing fault. We provide these specialist inspections for residential, commercial, and industrial properties across London and the M25, ensuring your installation remains compliant with safety standards. By using high-resolution infrared technology, our electricians can see what the naked eye cannot: internal resistance, overloaded circuits, and loose connections that generate excessive heat before they cause a breakdown.
Undertaking a Thermal Imaging Survey is a proactive step in preventive maintenance. For homeowners, landlords, and business managers, this service offers peace of mind by identifying fire risks early. Because the survey is conducted while the electrical system is under normal load, there is no need for costly downtime or power shut-offs. We simply scan your distribution boards, switchgear, and sockets to pinpoint exact areas of concern, allowing for targeted repairs rather than expensive, wide-scale investigative work.
What is an Electrical Thermal Imaging Survey?
In simple terms, this survey utilizes thermography to capture infrared radiation emitted by electrical components. All electrical items emit some heat during operation, but when a component is failing or under too much stress, the temperature rises significantly. These 'hotspots' are clear indicators of potential failure. Our qualified electricians use calibrated thermal cameras to map these temperature variations throughout your property’s wiring and distribution systems.
The resulting data provides a visual 'heat map' of your electrical infrastructure. Areas that appear bright yellow or white on the screen represent high temperatures, whereas healthy, functioning equipment will typically show as a cooler purple or blue. This allows us to assess the health of your installation without needing to strip back cables or dismantle consumer units unless a specific fault is confirmed.
Common Signs You Need a Thermographic Inspection
While a Thermal Imaging Survey is often used for preventive maintenance, there are several physical warning signs that suggest heat is building up within your walls or fuse boards. If you notice any of the following, a professional inspection is required to determine the severity of the heat buildup:
Ourselves and safety bodies recommend acting immediately if you experience these symptoms, as they often precede an electrical fire.
- —Discoloration, browning, or singe marks on socket faces or light switches.
- —A persistent smell of burning plastic or 'fishy' odours near electrical points.
- —Flickering lights or intermittent power loss that cannot be explained by bulb failure.
- —A consumer unit or fuse box that feels hot to the touch.
- —Buzzing or crackling sounds coming from behind the wall or inside panels.
- —Frequent tripping of RCDs or miniature circuit breakers (MCBs).
The Primary Causes of Electrical Hotspots
Heat is the byproduct of electrical resistance. In a perfectly functioning circuit, heat is dissipated safely. However, several factors can cause heat to rise to dangerous levels. One of the most common issues we find during a Thermal Imaging Survey is loose terminal connections. Over time, due to the natural vibration of current or the expansion and contraction of metals, screws in a distribution board can loosen. This creates high resistance, leading to rapid heating.
Another major cause is circuit overloading. When too many high-wattage appliances are running on a single circuit, the cables can exceed their rated capacity. Insulation may begin to degrade, creating a significant fire risk. We also frequently identify unbalanced loads in three-phase systems used by businesses, where one phase is working significantly harder than the others, leading to premature equipment failure and wasted energy.
The Risks of Ignoring Overheated Electrics
The risks associated with undetected electrical heat are severe. According to UK fire statistics, a large percentage of accidental fires in the home and workplace are caused by electrical faults. If a hotspot is left unaddressed, the heat will eventually melt the plastic insulation surrounding the copper conductors. Once the insulation fails, arcing can occur—where electricity jumps across a gap—reaching temperatures high enough to ignite surrounding building materials.
Beyond the risk of fire, there is the risk of total power failure. For a business, this could mean lost data, spoiled stock, or a complete halt in operations. For a homeowner, it could mean being left without heating or lights during the night. Regular thermographic testing ensures that these risks are managed before they escalate into an emergency situation.
What the Electrician Does During the Survey
When our electrician arrives to conduct the Thermal Imaging Survey, they will first discuss any known issues or' hotspots' you have noticed. The survey is non-destructive, meaning we do not need to move furniture or drill into walls. We will move through the property, scanning all accessible electrical points including consumer units, sub-mains, heavy machinery connections, and isolators.
During the process, we look for 'delta T' (temperature difference) readings. If one fuse is significantly hotter than its neighbours while carrying the same load, it is flagged as a fault. We document these findings with digital thermal images. If an immediate danger is found—such as a component currently at risk of ignition—we will inform you immediately and offer to isolate the circuit to make it safe.
What You Can Safely Check Yourself
Electricity is dangerous, and you should never attempt to open an electrical panel or dismantle a socket yourself. However, you can perform basic visual checks to maintain safety between professional surveys. Check that your plugs do not feel unusually warm and ensure there is plenty of ventilation around your consumer unit. Do not stack flammable materials like cardboard or coats over your fuse box.
If you suspect an issue, you can safely use your sense of smell and hearing. If you hear persistent 'arcing' noises, do not try to investigate. Simply turn off the power at the main switch if it is safe to do so and call a professional. Never touch any electrical fitting that is wet or shows signs of melting.
When Does a Hotspot Become an Emergency?
Not every warm component is an immediate emergency, but certain signs require an urgent 24/7 response. If you see smoke, sparks, or actual flames, you must call 999 immediately. Once the fire service has attended, or if you catch the fault before ignition, you need an emergency electrician to isolate the supply and prevent further damage.
If your consumer unit is emitting a loud buzzing sound or the smell of burning is strong, this is considered a high-risk situation. We operate across London and the M25 around the clock to handle these urgent faults. In many cases, the Thermal Imaging Survey we conduct during an emergency call-out helps us find the exact point of failure quickly, reducing the time you are left without power.
Professional Standards and Compliance
All our electrical work, including thermographic inspections, is carried out in accordance with BS 7671 (The IET Wiring Regulations). These are the UK standards for electrical installations. For businesses and landlords, having a record of these surveys contributes towards your health and safety compliance and can often be a requirement for building insurance policies.
Following the survey, we provide a report detailing our findings. This report categorizes issues by severity, allowing you to prioritize repairs based on risk. This structured approach to electrical maintenance is the most cost-effective way to manage a large property portfolio or a complex commercial site.
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Frequently asked questions
Do I need to turn the power off during the survey?
No, a Thermal Imaging Survey actually requires the power to be on. For the camera to detect heat, the circuits must be under load (in use). This makes it an ideal service for businesses that cannot afford to shut down their operations for testing.
Can the thermal camera see through walls?
Thermal cameras do not see 'through' objects, but they do detect the heat radiating from the surface. If a cable behind a plasterboard wall is significantly overheating, the heat will transfer to the surface of the wall, allowing us to identify the location of the fault.
Is thermography a replacement for an EICR?
No, it is a complementary service. An Electrical Installation Condition Report (EICR) involves physical testing and dead testing of circuits. Thermal imaging is an excellent addition that finds specific heat-related faults that traditional testing might miss, but it does not replace the mandatory safety requirements of an EICR.
How often should I have this survey performed?
For commercial environments with high power usage, an annual survey is recommended. For domestic properties, it is often performed if there are concerns about the age of the wiring or if the property has undergone significant renovation.
What should I do if I smell burning but can't see the source?
This is a potential emergency. If you cannot identify the source, you should turn off the electricity at the main consumer unit if it is safe to do so. Contact the network operator if you suspect the fault is with the incoming supply, and call an emergency electrician to investigate the internal wiring.