What should I do if my consumer unit catches fire?
Quick answer
If your consumer unit catches fire, do not attempt to open it or tackle the flames yourself. Get everyone out of the property immediately, call 999, and do not re-enter. If it is safe to do so without approaching the unit, switch off the main isolator switch outside or at the meter — but only if you can do this without risk. Never use water on an electrical fire. Once the fire service has attended and declared the property safe, you must have a registered electrician inspect and replace the consumer unit before any power is restored. This is a life-threatening emergency.
🏠Homeowner view
A consumer unit fire is one of the most serious electrical emergencies you can face at home. Consumer units — also called fuse boxes — contain live busbars, MCBs, RCDs, and wiring connections that carry the full incoming mains supply to your property. A fire here can spread rapidly into the wall cavity and roof space.
What to do right now:
Get everyone out of the property immediately, including pets
Call 999 — tell them it is an electrical fire at the consumer unit
Do not open the consumer unit door — this introduces oxygen and can cause flashover
Do not use water — electrical fires require a CO2 or dry powder extinguisher, but even these should only be used if you have been trained and the source of ignition is clearly isolated
Do not re-enter the property until the fire service declares it safe
If the main isolator or meter tails cutout is accessible outside the property or in a safe location away from the fire, you may switch this off — but only without putting yourself at risk
Common causes of consumer unit fires:
Loose or incorrectly torqued connections on busbars or MCB terminals
Overloaded circuits with undersized protective devices
Faulty or counterfeit MCBs or RCDs
Old plastic consumer units that do not meet current fire-resistance standards
Vermin damage to cable insulation inside the enclosure
Water ingress from a leak above the unit
After the fire service attends:
You must not restore power yourself under any circumstances
Contact a Part P registered electrician (NICEIC, NAPIT, or ELECSA registered) to inspect the installation
The electrician will need to carry out a full EICR (Electrical Installation Condition Report) before any new consumer unit is installed
Your home insurer must be notified — they may send their own assessor
Check whether your building control authority needs to be informed, as consumer unit replacement is notifiable work under Part P of the Building Regulations in England and Wales
Never assume the fire was minor and the rest of the installation is unaffected. Heat damage, smoke contamination, and thermal stress to cables can extend well beyond the visible burn area.