Consumer Unit Upgrades in London for Homes, Landlords & Businesses

A consumer unit, sometimes called a fuse box, is the main distribution point for the electrical circuits in a property. It contains the main switch and protective devices for circuits such as sockets, lighting, cooking equipment and electric showers. Its purpose is to distribute the supply and disconnect a circuit when an electrical fault or unsafe condition is detected.

An upgrade may be appropriate where the existing board is damaged, overheated, overcrowded, poorly labelled, unsuitable for planned new circuits or unable to provide the protection required by the installation. An EICR may also identify issues best resolved by replacement. The recommendation should be based on condition and suitability, not simply the age or appearance of the board.

No. An older or plastic consumer unit is not automatically unsafe and does not always require immediate replacement. The enclosure, internal components, circuit protection, signs of heat damage, earthing arrangements and overall installation condition should be assessed. Where replacement is agreed, the new consumer unit is selected to meet the applicable requirements at the time of installation.

Pre-upgrade checks normally include the supply arrangement, main earthing and bonding, circuit identification, insulation condition, polarity and the suitability of existing conductors. Testing can reveal faults such as low insulation resistance, shared neutrals or damaged circuits that may cause a new RCD or RCBO to trip. Any required remedial work is explained before the replacement proceeds.

An RCD monitors a group of circuits for earth leakage, while an RCBO combines residual-current protection with overload and short-circuit protection for one circuit. Individual RCBOs can reduce the number of circuits affected by a single fault and make fault identification easier. The correct arrangement depends on the installation design, circuit types, available space and connected equipment.

Individual RCBOs provide separate residual-current and overcurrent protection for each selected circuit. This can improve circuit separation because a fault on one circuit is less likely to disconnect unrelated circuits. RCBO type and rating must still be selected to suit the circuit, cable, load and equipment, so they are specified as part of the design rather than added as a generic upgrade.

A surge protective device, or SPD, helps limit transient overvoltages that could damage wiring or connected electronic equipment. SPDs are commonly fitted within a consumer unit, but the required type and arrangement depend on the supply and installation design. Whether an SPD is included should be confirmed in the quotation rather than assumed from the consumer unit price alone.

Not necessarily. Arc fault detection devices are considered according to the circuit, premises, intended use and the applicable wiring requirements at the time of design. They also require compatible equipment and sufficient space within the consumer unit. The quotation should identify where AFDD protection is required or recommended and explain the additional equipment cost.

The electricity supply must be safely isolated while the existing board is removed, the new unit is connected and testing is completed. Many straightforward domestic replacements can be completed within a working day, but the exact duration depends on circuit count, access, labelling and any faults found. Essential equipment, alarms or medical supplies should be discussed before the appointment.

A new consumer unit does not repair defective wiring. If testing identifies low insulation resistance, damaged conductors, incorrect connections, shared neutrals, missing earthing or another defect, the affected circuit may need repair before it can be safely energised. Minor work may be agreed during the visit, while larger or concealed faults normally require a separate quotation.

The price depends on the number of circuits, board size, protective-device arrangement, SPD or AFDD requirements, access, testing time and the condition of the existing installation. Earthing, bonding, meter-tail or circuit repairs may be additional when required. Electro Conduct confirms the scope after assessment and is not currently VAT registered, so VAT is not added.

Yes. In a dwelling in England, replacing a consumer unit is normally notifiable work under Part P of the Building Regulations. Notification is usually completed by an installer registered with a competent person scheme, or through the relevant building control route. The notification method and compliance documentation should be confirmed before the work is booked.

After replacement, you should receive the appropriate Electrical Installation Certificate with inspection and test schedules for the work completed. For notifiable domestic work in England, Building Regulations compliance documentation should also be provided through the applicable notification route. Circuit labels, protective-device details and instructions for operating test buttons should be supplied at handover.

Provide clear access to the consumer unit and share any previous certificates, EICRs or details of known faults. Safely shut down computers and sensitive equipment before the planned isolation. Tell the electrician about alarms, medical equipment, refrigeration, servers or other essential supplies, and mention any planned EV charger, solar, battery, heat-pump or high-load installation.