Consumer Unit Replacement: A Guide for Greenwich Homeowners

Consumer unit replacement is one of the most common electrical jobs we carry out across Greenwich and the surrounding SE postcode areas. Whether your fuse board is flagging on an EICR, causing regular nuisance tripping, or simply hasn't been touched since the 1980s, here's everything you need to know before booking.

What's a Consumer Unit and Why Does It Matter?

Your consumer unit — often called a fuse board — is the central hub of your electrical installation. It distributes power to all the circuits in your home and, crucially, provides protective devices that disconnect the supply when a fault develops. Without proper protection, a fault on any circuit could cause fire or injury.

Older consumer units — particularly the ceramic rewirable fuse boards found in Greenwich's Victorian terraces, post-war semis and 1960s estates — offer no meaningful RCD protection. When a fault develops, the fuse doesn't always blow fast enough to prevent damage. Modern consumer units isolate faulty circuits within milliseconds.

Signs You May Need a Replacement

• Ceramic rewirable fuses: These need to be physically replaced with fuse wire when they blow. Any board that still uses these should be upgraded.
• No RCD protection: If your board only has MCBs (the individual circuit breakers) and no RCD switches, it doesn't meet current safety standards.
• Plastic consumer unit: Since the 18th Edition of the Wiring Regulations (2018), new consumer units must be in metal enclosures to reduce fire spread risk. If yours is plastic, it will be flagged as C2 on an EICR.
• Frequent tripping: If breakers trip regularly without obvious cause, the board itself may be worn.
• EICR result: If your inspection has flagged the consumer unit as C2 — which is very common in older Greenwich properties — replacement is the most practical remedy.

What Gets Installed

We install dual-RCD or fully RCBO-protected consumer units in metal enclosures. RCBOs — which combine the function of an MCB and an RCD in a single device — give each circuit its own independent protection. This means a fault on one circuit doesn't trip the entire board and affect the rest of the property.

The unit is housed in a metal enclosure as required by current regulations. Every circuit is individually tested before the supply is restored and an Electrical Installation Certificate is issued the same day.

What the Job Involves

The supply will be off for the duration of the work — typically 4–6 hours for a standard 3–4 bedroom property. We aim to start early and restore power well before the end of the working day. On the day:

1. The supply is isolated at the meter
2. All circuits are disconnected from the old board
3. The new consumer unit is mounted and wired
4. All circuits are reconnected and individually tested
5. A test schedule is completed and the supply is restored
6. The Electrical Installation Certificate is issued by email

Is It Notifiable Work?

Yes. Consumer unit replacement is notifiable under Part P of the Building Regulations. We handle the notification on your behalf and you receive the Part P certificate as part of the job. You'll need this for any future sale of the property.

What Does It Cost in Greenwich?

Most consumer unit replacements across Greenwich and the SE postcode areas come in between £350 and £600. The variation is mainly down to the number of circuits. Larger properties or those requiring additional work — additional bonding, extra circuits, smoke alarms — will be at the higher end. We quote a fixed price before starting and don't adjust it on the day.