Do You Need a Consumer Unit Replacement? Signs to Look For

Consumer unit upgrades are one of the most common jobs we carry out in Petts Wood, Orpington and the surrounding Bromley Borough. The area's 1930s housing stock means many properties still have electrical installations that haven't been comprehensively updated since they were first fitted — and the consumer unit is often where that shows most clearly.

What Is a Consumer Unit?

The consumer unit — sometimes called the fuse box or fuse board — is the distribution point for all electrical circuits in your property. It contains the main switch, circuit breakers (MCBs) for each individual circuit, and RCDs (residual current devices) that cut power if a fault is detected. Modern consumer units use a combination of these to protect both the circuits and the people using them.

Signs Your Consumer Unit May Need Replacing

It contains rewirable fuses. These are ceramic holders with thin wire inside that melts when a circuit is overloaded. They were standard until the 1970s and are still found in a significant number of Petts Wood's 1930s and 1940s semis. They offer no RCD protection and are considered obsolete by modern standards.

It's a plastic consumer unit. From 2016, the 18th Edition Wiring Regulations required new and replacement consumer units to be housed in non-combustible enclosures — typically metal. A plastic consumer unit isn't automatically unsafe, but it's a C2 finding on an EICR and will need replacement if you're a landlord.

There are no RCD switches on the board. If your consumer unit only has MCBs and no RCDs or RCBOs, it doesn't provide protection against electric shock from earth faults. This is now a standard requirement for all circuits.

The board trips frequently. A consumer unit that keeps tripping — or where switches refuse to stay up — either has an underlying fault that needs finding, or the unit itself has developed a fault. Either way it needs attention.

Your EICR has flagged it. Consumer unit issues are among the most common C2 findings in EICRs we carry out in the Petts Wood area.

What Does a Consumer Unit Replacement Involve?

We install a new metal-enclosed consumer unit with dual-RCD or full RCBO protection, remove the old unit and reconnect all circuits. The incoming supply is isolated at the meter while we work. We test every circuit after reconnection before restoring the supply, then issue a Part P Electrical Installation Certificate.

For a typical 3-bedroom Petts Wood semi, the job takes approximately 4–6 hours. You'll be without power while we work, so it's worth planning around that if you work from home.

How Much Does It Cost in Petts Wood?

Most consumer unit replacements in the Petts Wood and Orpington area cost between £350 and £600. The variation depends on the number of circuits, whether any additional bonding or earthing is needed, and whether there are other remedial items to address at the same time. We confirm a fixed price before we start — nothing changes on the day.

Do You Need an EICR First?

If you already know the consumer unit needs replacing — because it's an old rewirable type or your current EICR has flagged it — you don't necessarily need a fresh EICR first. However, we'll test all circuits during the replacement and can identify any further issues. Many customers choose to combine an EICR and consumer unit upgrade in a single visit, which is more cost-effective and time-efficient.