Your consumer unit — the fuse box — is the heart of your home’s electrics and its main safety device. An outdated one isn’t just inconvenient; it can leave you without modern shock and fire protection. Here’s how to tell yours is due for replacement.

1. It has rewireable fuses

If your “fuses” are wire that you replace by hand (rather than switches you flick back on), the board is old — typically decades — and lacks modern protection. This is the clearest sign it’s time to upgrade.

2. There’s no RCD protection

An RCD cuts power in milliseconds when it detects current leaking to earth — the protection that can stop a fatal shock. If your board has only MCBs (or fuses) and no RCD, you’re missing the single most important safety device in a modern installation. Our RCD vs RCBO guide explains why this matters.

3. It’s a cracked or old plastic/metal-clad unit

Older plastic consumer units, or aged metal-clad boards, may not meet current standards. Since 2016, new domestic boards are required to be non-combustible (metal) — a cracked or scorched older unit is a clear candidate for replacement. (See our plastic vs metal consumer unit guide.)

4. Nuisance tripping

If one faulty appliance trips the whole board and plunges half the house into darkness, that’s a sign of an old shared-RCD or rewireable setup. A modern board with per-circuit RCBOs isolates faults to one circuit — far less disruptive. Persistent tripping is worth investigating.

5. Scorching, buzzing, or a burning smell

Brown marks, a buzzing board, or a burning smell at the consumer unit are serious — switch off if safe and call an electrician urgently. A board showing heat damage needs replacing.

6. It’s full — no spare ways

If you want to add a circuit (an EV charger, an electric shower, a garden supply) and the board has no spare ways, replacing it with a larger modern unit is usually the practical solution — and a good moment to add full protection.

7. Your EICR flagged it

An EICR often codes an old board — for example C2 for no RCD protection. That makes the report unsatisfactory and means the board should be upgraded. See our EICR codes guide.

8. You’re adding modern loads

Heat pumps, EV chargers, electric showers, and battery storage all add demand. An ageing board may not safely support them, so an upgrade often goes hand in hand with these projects.

Is it the board, or the whole installation?

A board upgrade is sometimes all that’s needed — but if the wiring behind it is also old, an electrician may recommend addressing both. Importantly, fitting a new consumer unit means the existing circuits must be tested, and a good electrician won’t fit a shiny new board onto dangerous old wiring without telling you. If wider problems show up, see our signs your house needs rewiring guide.

What a new board gives you

• RCD/RCBO protection against shock and fire
• Per-circuit isolation so faults don’t black out the house
• A non-combustible metal enclosure to current standards
• Spare capacity for future circuits
• Full certification and BS 7671 compliance

Thinking of upgrading?

If your board ticks any of these boxes, an assessment will confirm whether a straightforward consumer unit replacement is the answer. GFL Electrical upgrade consumer units across East London. See our fuse box replacement service or call 020 3774 5604.