How to Troubleshoot Common EV Charger Faults Before Calling an Engineer

As electric vehicles (EVs) continue to rise in popularity across the UK, home EV chargers have become an essential part of modern living. But like any electrical appliance, your charger may occasionally encounter problems. While it’s always safest to have serious electrical faults inspected by a qualified engineer, there are several basic troubleshooting steps you can take to identify and potentially fix common issues yourself.

In this blog, we’ll walk you through the most common EV charger faults, explain what may be causing them, and show you what to try before calling out a professional. Whether you own a tethered or untethered home charger, these tips could save you time, money, and unnecessary frustration.

First Things First: Safety Matters

Before we jump in — a quick but important reminder:

If you smell burning, see visible damage, or suspect a serious electrical fault — turn off the charger at the consumer unit (fuse board) and call a qualified EV electrician immediately.

Never attempt to open or tamper with the internal components of your EV charger. These units carry high voltage and should only be serviced by certified professionals, such as the team at Danlec Electrical.

1. Your Charger Isn’t Powering On

Symptoms: No lights on the charger, display is blank, EV doesn’t charge at all.

What to check:

• Circuit Breaker:
  Go to your consumer unit and check if the circuit breaker for the charger has tripped. If it has, reset it. If it trips again immediately, stop and call an electrician — this indicates a fault in the wiring or unit.
  
• RCD/RCBO Protection:
  Some chargers have built-in RCD protection. Check if the device has tripped. If so, reset it — but do not repeatedly reset without understanding the cause.
  
• Isolated Supply Switches:
  Ensure the charger’s isolation switch (if fitted) is in the “on” position. Sometimes these are accidentally switched off during DIY or garden work.
  

If none of the above work:
There may be an internal power supply fault — in which case, call an EV charger engineer.

2. Charging Starts, Then Stops Unexpectedly

Symptoms: Charging begins as normal, then cuts off after a few minutes or intermittently.

What to check:

• Loose Charging Cable:
  For untethered units, ensure the cable is fully inserted into both the charger and the vehicle. A loose connection can trigger charging interruptions.
  
• Check for Timer Settings:
  Some EV chargers (like Hypervolt or Zappi) have scheduling features that allow users to set specific charge times. These may clash with your current charging attempt. Use the charger’s app or interface to review your settings.
  
• Vehicle Battery Already Full:
  Modern EVs stop drawing current when the battery reaches full capacity. Double-check your vehicle’s dashboard.
  
• Overheating (Thermal Cut-out):
  On very hot days, your charger may stop temporarily to prevent overheating. If so, wait for it to cool down and try again later.
  

3. No Internet or App Connectivity

Symptoms: You can’t connect to the charger via the app or Wi-Fi.

What to check:

• Wi-Fi Signal Strength:
  If your charger is far from your router, poor signal could disrupt app connectivity. Consider moving your router, using a Wi-Fi extender, or switching to an Ethernet connection (if supported).
  
• Reset the Charger’s Network Settings:
  Follow the instructions in your model’s manual to reset the network settings and reconnect it to Wi-Fi.
  
• App Update Needed:
  Check your phone’s app store for updates to your charger’s companion app.
  

Still no luck?
The internal Wi-Fi module or firmware may be faulty. Contact a professional installer like Danlec to inspect it.

4. Strange Lights or Error Codes on the Charger

Most EV chargers have LED indicators or error codes that offer clues to what’s wrong.

Common colours and what they mean:

Light Colour	Meaning
Solid Green	Ready/charging successfully
Flashing Blue	Waiting for scheduled time
Solid Red	Fault/error – check manual
Flashing Red	Ground fault or RCD tripped

What to do:

• Refer to your charger’s user manual or brand support page (e.g. MyEnergi, EO, Rolec, Hypervolt) to understand the code or flashing pattern.
  
• Power cycle the unit (turn it off at the isolation switch or consumer unit, wait 10 seconds, and turn it back on).
  
• If the error persists, it’s time to call a qualified technician.
  

5. Slow Charging or Lower Power Output Than Expected

Symptoms: Charging takes significantly longer than usual.

What to check:

• Are You Using a Granny Cable?
  Some EVs default to a 3kW charge rate when using a portable plug-in cable. Compare with your wall-mounted charger’s output (typically 7kW for single-phase homes).
  
• Peak Time Restrictions:
  Some chargers restrict current draw during grid peak hours to help prevent overloading. Check your app’s eco or load-balancing settings.
  
• Check Fuse Ratings:
  If your home supply has low-rated fuses or your charger was not installed with enough capacity, it may be operating at reduced power for safety.
  

If none of the above apply, a professional inspection may be needed to check the charger’s internals or your property’s electrical load balance.

When to Call Danlec Electrical

If basic checks don’t resolve your issue, or if you encounter any of the following, stop troubleshooting and get in touch:

• Burning smells or smoke from the unit
  
• Repeated RCD or fuse tripping
  
• Physical damage or corrosion on the charger
  
• Charger installed over 3 years ago and never serviced
  
• Frequent disconnections or random shutdowns
  

At Danlec, we’re fully qualified to repair, replace or upgrade home EV chargers across the UK. We work with all major brands, provide fixed-price callouts, and ensure all work is Part P and OZEV compliant.

Bonus Tip: Prevent Problems with Regular Maintenance

Just like a boiler or solar system, your EV charger should be serviced regularly — especially if it’s exposed to outdoor conditions.

Danlec offers annual EV charger servicing, which includes:

• Safety tests
  
• RCD trip checks
  
• Cleaning of contacts
  
• Firmware updates (where applicable)
  
• Inspection of cable condition and load capacity