EV Charger Overheating? Causes & Fixes Explained

As electric vehicles become more common across the UK, home charging points are now an essential part of everyday life. When everything works as it should, charging is simple and efficient. But if you notice your unit becoming excessively hot, shutting down unexpectedly, or triggering safety warnings, you may be dealing with EV Charger Overheating.

At EVC Electrical Installations Ltd, we regularly assist homeowners and businesses with diagnosing and resolving EV charger issues. Overheating is not something to ignore. While many modern chargers include built-in safety protections, persistent temperature problems can indicate installation faults, electrical capacity issues, or environmental factors.

If your charger is running hotter than usual and you want professional guidance, contact our team today.

Is EV charger overheating normal?

It’s important to understand that some heat is completely normal during charging. EV chargers handle high electrical loads for extended periods, which naturally generates warmth.

However, EV charger overheating becomes a concern when:

• The unit feels excessively hot to the touch
• Charging sessions stop unexpectedly
• The charger displays temperature-related error codes
• Circuit breakers trip during charging
• You notice a burning smell

Modern chargers include thermal sensors to reduce power or shut down if temperatures rise too high. If this happens frequently, it’s time to investigate.

Common causes of EV charger overheating

Several factors can contribute to excessive temperature build-up. Identifying the correct cause is key to safe resolution.

1. Inadequate electrical supply or overloaded circuits

If your property’s electrical system is not designed to handle sustained high loads, wiring may overheat during charging. This is particularly common in older homes without upgraded consumer units.

An undersized cable or incorrectly rated breaker can cause EV charger to overheat, as the system struggles to manage the demand.

2. Poor installation or loose connections

Loose terminals or improper wiring create resistance within the circuit. Electrical resistance generates heat.

Even minor connection issues inside the charger or at the consumer unit can gradually lead to temperature increases. Professional installation is essential to prevent these risks.

3. Limited ventilation

EV chargers installed in enclosed spaces without airflow may retain heat. Garages with poor ventilation can amplify temperature build-up, especially during long charging sessions.

Outdoor units exposed to direct sunlight can also overheat during warm weather.

4. High ambient temperatures

In summer months, charging in direct sunlight can increase surface temperatures. Combined with internal heat generation, this may trigger protective shutdown mechanisms.

While modern chargers are designed to operate outdoors, excessive heat combined with heavy usage can increase the risk of EV charger overheating.

5. Damaged charging cables

Worn or damaged cables create electrical inefficiencies and resistance. This can result in localised heating at connection points.

Always inspect your charging cable for:

• Cracks
• Frayed insulation
• Bent connectors
• Loose fittings

Warning signs you should not ignore

Even if your charger continues working, certain symptoms indicate underlying problems.

Look out for:

• Repeated breaker trips
• Frequent power reduction during charging
• Unusual buzzing or clicking noises
• Discolouration around plug connections
• Error codes on your charger display

Persistent EV charger overheating should always be investigated by a qualified electrician.

How to troubleshoot minor overheating issues

Before calling an engineer, there are a few safe checks you can carry out:

• Ensure the charger is not obstructed or covered
• Check that ventilation around the unit is clear
• Avoid charging during peak daytime heat if installed in direct sunlight
• Confirm that the cable is fully inserted and secure
• Reduce charging speed temporarily if your unit allows it

If overheating continues, do not attempt internal inspection yourself.

When professional intervention is necessary

If the issue persists, professional assessment is essential. A qualified installer will typically:

• Test the electrical load capacity
• Inspect wiring and cable ratings
• Check terminal connections
• Verify breaker and RCD protection
• Confirm compliance with installation standards

Addressing EV charger overheating early prevents long-term damage to wiring, the charger unit, or even your vehicle’s onboard charging system.

Prevention tips to avoid overheating problems

Prevention is always better than repair. To reduce the risk of overheating:

• Ensure installation is carried out by a certified electrician
• Upgrade your consumer unit if necessary
• Avoid overloading circuits
• Schedule periodic electrical inspections
• Keep the charger clean and unobstructed
• Use manufacturer-approved cables only

Regular maintenance helps extend the lifespan of your charging system and ensures continued safety.

Why correct installation matters

The most common long-term cause of EV charger overheating is improper installation. EV chargers draw continuous high current, meaning wiring must be appropriately rated and protected.

A compliant installation includes:

• Correct cable sizing
• Dedicated circuit protection
• Proper earthing arrangements
• Surge protection where required
• Load balancing where necessary

Professional installation ensures your charging point operates safely within your property’s electrical capacity.

How weather and environment affect charger performance

Environmental exposure plays a larger role than many realise. Coastal properties may experience corrosion over time. High dust areas can affect ventilation. Direct UV exposure can heat unit casings.

Choosing a suitable installation location reduces environmental stress and improves performance stability.

Can EV charger overheating damage your vehicle?

Most modern vehicles include built-in safeguards to prevent battery damage. However, inconsistent charging due to repeated shutdowns can affect convenience and efficiency.

Persistent overheating may also damage charging connectors over time. Addressing the root cause protects both infrastructure and vehicle longevity.

How EVC Electrical Installations Ltd can help

At EVC Electrical Installations Ltd, we specialise in safe, compliant EV charging solutions. Whether diagnosing EV charger overheating, upgrading electrical capacity, or installing a new charging point, our focus is on long-term reliability.

We provide:

• Professional EV charger installation
• Electrical capacity assessments
• Consumer unit upgrades
• Fault diagnosis and repairs
• Ongoing maintenance advice

Our goal is to ensure your charging setup remains safe, efficient, and future-ready.

Don’t ignore overheating signs

A warm charger is normal. A hot charger is not. Persistent EV charger overheating is a warning sign that should be addressed promptly.

With the right diagnosis and professional support, most overheating issues can be resolved quickly and safely. Acting early protects your home, your vehicle, and your peace of mind.

If you are experiencing overheating issues or planning a new EV charger installation,  contact our team today.