Do I Need to Replace My Consumer Unit? A Homeowner's Guide

A Litt • 16 August 2025

Fuse Box or Consumer Unit is it Replacement Time

Your consumer unit, also known as a fuse box, is the heart of your home’s electrical system. It protects you and your family by managing and distributing electricity safely. But what happens when this crucial component gets old or can’t keep up with modern electrical demands? How do you know when it’s time for an upgrade?

This guide from 786 Electricals Limited answers the most common questions about consumer unit replacements and helps you understand the signs that it may be time for an upgrade.

How Do I Know When to Replace My Consumer Unit?

If your home’s electrical system is the heart, the consumer unit is the main artery. Like any vital component, it will show signs of age or a need for replacement. These are the key indicators that you should have your consumer unit checked by a qualified electrician:

Frequent Tripping or Blown Fuses: Your circuit breakers are designed to trip when a circuit is overloaded. If this happens often, your current consumer unit may not be able to handle the number of appliances you are using.
Burn Marks or Scorching: Any signs of heat damage, such as discoloration or burn marks on or around the consumer unit, are an immediate and serious fire hazard.
Hearing Strange Noises: Loud buzzing or crackling sounds coming from your fuse box can indicate loose wiring or a faulty component.
Old-Fashioned Fuses: If your unit has traditional wire fuses instead of modern circuit breakers, it lacks the advanced safety features of modern units, such as MCBs (Miniature Circuit Breakers) and RCDs (Residual Current Devices).
Lack of RCD Protection: Residual Current Devices are essential for preventing fatal electric shocks. If your current unit doesn't have them, it should be upgraded.
The Age of the Unit: Most consumer units installed before 2000 do not meet current UK electrical regulations (BS 7671). If your unit is over 20 years old, it's very likely due for an upgrade.

If you notice any of these issues, it is crucial to consult a qualified electrician. Don't attempt to fix it yourself—the potential risks are too great.

Why Is a Consumer Unit Upgrade So Important?

Replacing an old consumer unit isn't just about compliance; it's a vital safety measure. A modern unit offers:

Enhanced Safety: Modern units include RCDs and MCBs, which provide much better protection against electrical faults and electric shocks.
Increased Capacity: Today's homes use more power than ever. A new consumer unit is designed to safely handle the electrical demands of modern appliances without risking overloads.
Compliance with Regulations: Upgrading ensures your home meets the latest British wiring regulations (BS 7671), which can be important for home insurance and future sales.
Potential to Increase Property Value: A safe, modern electrical system is a major selling point for potential buyers.

How Much Does a Consumer Unit Replacement Cost?

The cost of a consumer unit replacement varies based on several factors, including:

The number of circuits in your home.
The complexity of your current wiring.
Whether additional work, such as partial rewiring, is required.

In the UK, the cost typically ranges from £500 upwards, which includes both the new unit and professional labor. At 786 Electricals Limited, we provide a full, detailed quote after a professional on-site assessment, so you know exactly what to expect.

Why Can't I Replace My Consumer Unit Myself?

A consumer unit replacement is not a DIY job. It is a complex and dangerous task that must be carried out by a certified professional. Attempting to do it yourself can result in serious injury, electrical fires, or damage to your home.

A qualified electrician ensures:

Safe and correct installation.
Compliance with all UK wiring regulations.
Proper testing and certification (you will be provided with a BS 7671 Electrical Installation Certificate).