Consumer Unit Upgrade: Do You Need One?

Your consumer unit — commonly called a fuse box — is the heart of your home's electrical system. If it's outdated, it could be putting your property and family at risk. Here's how to know if yours needs upgrading.

What does a consumer unit do?

The consumer unit distributes electricity to all the circuits in your home and provides protection against electrical faults. Modern units contain RCDs (Residual Current Devices) that instantly cut the power if a fault is detected, and MCBs (Miniature Circuit Breakers) that protect individual circuits from overloading.

Signs your consumer unit needs replacing

If your fuse box still uses rewirable fuses instead of MCBs, it's outdated and should be replaced. Other signs include frequently tripping breakers, a wooden or cast iron fuse box, no RCD protection, burn marks or scorch damage, and a buzzing or humming sound coming from the unit.

If your property was built before 2000 and the consumer unit hasn't been upgraded, it's worth having it inspected by a qualified electrician.

Why upgrade?

A modern consumer unit with RCDs can detect an electrical fault and cut the power in milliseconds — fast enough to prevent electrocution. Older fuse boxes without this protection are significantly more dangerous. An upgrade also means better protection against electrical fires, compliance with current regulations (18th Edition BS 7671), and potentially fewer nuisance trips once circuits are properly allocated.

What does the upgrade involve?

A consumer unit upgrade typically takes half a day. The electrician will isolate the power, remove the old unit, install the new one, and reconnect all circuits. They'll test every circuit to ensure everything is working correctly. You'll receive an Electrical Installation Certificate upon completion.

The power will need to be off for several hours during the work, so it's worth planning around this.

How much does a consumer unit upgrade cost?

Costs vary depending on the number of circuits and the condition of existing wiring. Additional work may be needed if the earthing or bonding doesn't meet current standards. We provide free quotes with a full breakdown of costs before any work starts.

Is it a legal requirement?

While there's no legal requirement for homeowners to upgrade, landlords must ensure their electrical installations are safe, and an outdated consumer unit may fail an EICR. If you're selling your home, an upgraded consumer unit is a positive selling point. For any new electrical work, the consumer unit must meet current 18th Edition standards.

We carry out consumer unit upgrades across South London and Kent. All work is NICEIC certified with Part P notification. Call 020 3576 2747 for a free quote.