What is this?
A lightning strike on or near a property can send a massive surge through the electrical installation, damaging or destroying protective devices, wiring, appliances, and electronics. Even a nearby strike (within a few hundred metres) can induce a surge in the mains supply sufficient to damage sensitive equipment. Direct strikes can cause structural damage, fires, and complete destruction of the consumer unit.
Common causes
- Direct lightning strike to the property or its supply cable
- Nearby lightning strike inducing a mains surge through the supply network
- Lightning strike to a tree or structure that earths through the property's electrical system
- Surge entering through telephone, broadband, or TV aerial cables
- Induced voltage spike from a strike on the local electricity network
Is it dangerous?
A lightning strike is an emergency. If there is any sign of fire, burning smell, or structural damage, call 999 immediately. Even without visible damage, lightning can cause hidden faults in wiring insulation that create ongoing fire and shock risks. Do not use any electrical equipment until the installation has been professionally inspected.
Can I fix it myself?
Check for any signs of fire or burning and call 999 if found. Do not touch the consumer unit if it appears damaged or scorched. If you can safely reach it and it appears undamaged, turn off the main switch as a precaution. Unplug all sensitive electronics. Do not attempt to repair any lightning-damaged equipment yourself.
When to call an electrician
Call an electrician urgently after any lightning strike that has affected your electrics. A full Electrical Installation Condition Report is essential to identify any hidden damage. If the consumer unit has been damaged, it will need replacing before power can be restored.
What will an electrician do?
Inspect the consumer unit for surge damage to MCBs, RCDs, and busbars
Test all circuits for insulation damage caused by the voltage surge
Replace any damaged protective devices and the consumer unit if necessary
Check the earthing system for damage, as lightning can degrade earth electrodes
Install surge protection devices (SPDs) to protect against future surges
Issue a full EICR and any necessary installation certificates
Typical cost
£200 – £800
Inspection and repair after a lightning strike. Consumer unit replacement is £350–£600. Surge protection device installation is £150–£300 additional. Insurance typically covers lightning damage.
