What Is a Consumer Unit?
A consumer unit distributes electricity from your meter to every circuit in your home. It contains circuit breakers (MCBs) that trip to protect individual circuits, and Residual Current Devices (RCDs) that cut power instantly if they detect a fault to earth -- preventing electric shock and reducing fire risk. Modern consumer units are a critical safety component, not just a distribution point.
Why Upgrade Your Fuse Board?
Regulation Changes
Amendment 3 to the 17th Edition, BS 7671:2008 (effective January 2016), requires all new consumer units in domestic premises to be made from non-combustible material -- typically a steel or metal enclosure. If your consumer unit is a plastic model installed before 2016, or an even older rewirable fuse board, it does not meet this standard. While there is no legal requirement to upgrade, the safety benefits are significant.
Safety Risks of Old Fuse Boards
Rewirable fuse boards with wire fuses offer no RCD protection. This means there is nothing to detect a fault to earth -- the most common cause of fatal electric shocks. Plastic consumer units installed before 2016 can melt and catch fire in fault conditions. Every year in the UK, electrical faults cause around 14,000 house fires. Upgrading your consumer unit is one of the most effective ways to protect your home.
Other Reasons to Upgrade
- Adding circuits -- if you are installing an EV charger, extending your property, or adding a garden office, you will need spare ways in your consumer unit.
- Selling your property -- buyers and surveyors will flag outdated fuse boards. An upgrade adds value and speeds up sales.
- After an EICR -- if your EICR inspection identifies C2 (potentially dangerous) codes related to your consumer unit, upgrading is the recommended remedial action.
- Insurance -- check your insurance policy for any conditions about the condition of the electrics.
What Does the Upgrade Involve?
A consumer unit upgrade is a notifiable job under Part P of the Building Regulations: it must either be done by an installer registered with a competent person scheme (who self-certifies), checked by a registered third-party certifier, or notified to building control before work starts. Here is the typical process:
- Assessment -- we inspect your existing consumer unit, count circuits, check earthing and bonding, and assess the condition of your wiring.
- Installation -- the old unit is removed and a new metal consumer unit is fitted with RCBO protection on every circuit. This typically takes 4-6 hours.
- Testing -- every circuit is tested to BS 7671:2018 standards. We check insulation resistance, earth fault loop impedance, polarity, and RCD trip times.
- Certification -- you receive an Electrical Installation Certificate (EIC), and the work is registered with NAPIT and your local Building Control.
Types of Consumer Unit
Dual RCD Split-Load
The most common type. Two RCDs each protect half of your circuits. Cost-effective and reliable, though a fault on one circuit will trip the RCD and cut power to all circuits on that side. We do not fit these: every board we install is a full RCBO board.
RCBO Board
Every circuit has its own RCBO (combined MCB and RCD). If a fault trips one circuit, all other circuits remain live. It provides the highest level of protection and convenience. This is the only type of board we fit: a main switch with a Type A RCBO on every circuit, on every job.
High-Integrity Board
A hybrid approach with three RCDs -- critical circuits like lighting and freezers are on a dedicated RCD, while remaining circuits are split across two more. We do not fit these either: every board we install is a full RCBO board.
How We Price a Consumer Unit Upgrade
We price every board change individually, because no two installations are the same. The price depends on how many circuits the new board needs to serve, where it is going, and the condition of the existing wiring, earthing and bonding. Our quote covers supply and fit, full testing, certification and NAPIT registration. If additional remedial work is needed, for example upgrading earthing and bonding, we explain exactly what is required and why, and you have a fixed written price before any work starts.
How Long Does It Take?
A standard consumer unit upgrade takes 4-6 hours for a straightforward swap. During installation, power will be off to your property. We always aim to complete the work in a single day and will confirm the expected duration when we provide your quote. For larger properties or those requiring additional circuit work, it may extend to a full day.
Frequently Asked Questions
Is it a legal requirement to upgrade?
There is no law requiring you to replace an existing consumer unit simply because it is old. When new work is added, the new work must meet current standards and the existing installation (including the consumer unit, earthing and bonding) must be adequate for it — sometimes that means upgrading the board. Landlords must also ensure their properties pass an EICR every 5 years, and outdated consumer units frequently cause failures.
Can I upgrade the consumer unit without a full rewire?
Yes, in most cases. If the existing wiring is in reasonable condition, a consumer unit upgrade can be carried out independently. We will test the existing circuits during installation and let you know if any wiring issues need addressing. In many homes across Frome, Midsomer Norton, and Street, a consumer unit upgrade alone is sufficient to bring the installation up to a satisfactory standard.
Why Choose DS Electrical?
- NAPIT Approved -- all work self-certified and registered with Building Control
- City & Guilds qualified -- 18th Edition, inspection and testing
- Fixed prices -- the price we quote is the price you pay
- Local coverage -- Wells, Shepton Mallet, Bath, Frome, Midsomer Norton, Street, and surrounding areas