Consumer Unit Upgrades & Fuse Board Replacements

Our consumer unit upgrades start from £950. That includes the new unit, RCD and RCBO protection, a surge protection device, circuit labelling, full testing, the NICEIC Electrical Installation Certificate and Part P Building Regulations notification. The final price depends on the number of circuits and any additional work required — you’ll always get a written fixed-price quote before we start.

They’re the same thing — consumer unit is the modern term for what used to be called a fuse box or fuse board. Older fuse boards use wire fuses or early MCBs without RCD protection. A modern consumer unit uses RCBOs or RCDs alongside MCBs, protecting against both overloads and electric shock. Current wiring regulations (BS 7671:2018+A4:2026) require RCD protection on most circuits.

Most upgrades take between half a day and a full day. Your power will be off while we isolate, remove the old unit, install and test the new one. We agree the timing in advance to keep disruption to a minimum — the total off-time is usually two to four hours depending on the number of circuits.

No — only during the installation itself. We isolate the supply, carry out the swap, reconnect and test each circuit, then restore power. We’ll let you know before and after the supply goes off so you can plan around it.

Not always, but often. EV chargers require a dedicated circuit, and if your existing board is old, full, or lacks RCD protection, an upgrade is usually needed at the same time. We assess this as part of the EV charger survey and can quote for both together where required.

BS 7671:2018 recommends surge protection devices (SPDs) on all new consumer unit installations. An SPD protects your appliances and electronics from voltage spikes caused by nearby lightning or switching surges on the network. We include one as standard on every new consumer unit we fit.

A C1 code means danger present and immediate action is required. A C2 means potentially dangerous and should be addressed promptly. Both codes on a consumer unit typically mean it needs replacing. We’ll explain the findings clearly and provide a written quote for the upgrade — often at the same visit as the EICR.

Yes. After fitting the new unit we carry out full circuit testing — insulation resistance, continuity and RCD tests — before issuing the certificate. If testing finds a fault on a circuit we’ll advise you and quote for remedial works separately. Nothing hidden.

Yes. Consumer unit upgrades are notifiable under Part P of the Building Regulations. You’ll receive an NICEIC Electrical Installation Certificate — your legal proof the work meets the current standard. We also notify Building Control on your behalf as part of the job.

Yes — we’re based in Chislehurst and carry out consumer unit upgrades regularly across Blackheath, Bickley, Bromley, Lee, Eltham, Greenwich and across SE London.