Your consumer unit—commonly called the fuse board—is the hub of your home's electrical protection. Older units fitted with rewirable fuses or early MCBs without RCD protection may no longer offer the level of safety expected from a modern installation.
Understanding the warning signs can help you decide when to request an assessment. One of the most common indicators is a consumer unit that trips frequently or fails to reset properly after a trip.
If a particular circuit trips whenever a certain appliance is used, there may be an underlying fault in the wiring or the device itself—but it can also indicate that the board's protective devices are ageing or undersized for the current load. Visible signs of deterioration include scorching or burn marks around the consumer unit casing, a smell of burning plastic near the board, or loosely fitting circuit breakers that no longer click firmly into position.
Some older boards use cartridge fuses or rewirable wire fuses rather than MCBs, and while these were once standard, they do not provide the same speed or accuracy of protection as modern devices. If your property was built or last rewired before the 1990s and the consumer unit has never been replaced, it almost certainly pre-dates modern RCD protection.
A qualified electrician can inspect the board, carry out continuity and insulation resistance tests on the circuits feeding it, and advise whether replacement is appropriate.