Consumer Unit Upgrades in Cardiff
Replace your old fuse board with a modern 18th Edition consumer unit. Full RCD or RCBO protection. NAPIT building regs notification included. Free survey, no call-out fee.
The consumer unit is the metal box on the wall that houses your circuit breakers. You might know it as the fuse board or fuse box. Every circuit in your home runs back to it. The consumer unit controls and protects each circuit, and when something goes wrong, a properly specified unit trips the relevant breaker before serious damage can occur.
Older boards, some still using wire fuses or early RCDs, don't meet the current 18th Edition wiring regulations. They also lack the protection levels that modern usage demands. If your board is more than 20 years old, or if it's been flagged on an EICR, it needs replacing.
Signs you need a consumer unit upgrade
Tripping breakers
If breakers trip regularly, or a fuse keeps blowing, the board may be undersized for modern demand or faulty.
Failed EICR
An unsatisfactory EICR will often flag the consumer unit, particularly if it has no RCD protection or uses outdated components.
Selling your home
Buyers, mortgage lenders and insurers all look at the consumer unit. An old board can delay or kill a sale.
No RCD protection
Older boards may have no RCD at all. Without it, there's no protection against electric shock from a fault on socket circuits.
Insurance issues
Some insurers won't cover properties with older boards, or will apply exclusions. An upgraded unit resolves this.
Adding new circuits
Installing an EV charger, hot tub or garden office often requires new circuits. If the board has no spare ways, it needs replacing.
What does a consumer unit upgrade involve?
We isolate the mains supply at the meter tails, remove the old board and fit the new consumer unit in its place. All the existing circuit cables are reconnected, labelled and tested. Once testing is complete, we restore power circuit by circuit, running final checks as we go.
We'll carry out a visual inspection of the installation before starting. If we spot anything else that needs attention, we'll tell you before the work begins, not after.
RCD vs RCBO protection
Both RCDs and RCBOs protect against electric shock by detecting earth leakage and cutting the power within 40 milliseconds. The difference is in how they group your circuits.
RCD Board
A dual-RCD board splits your circuits between two RCDs. If one RCD trips, half your circuits go off. Lower upfront cost.
- Two RCD banks protect all circuits
- Common in domestic upgrades
- Lower cost than RCBO
- Half the circuits trip together
RCBO Board
Each circuit gets its own RCBO device. If one circuit has a fault, only that circuit trips. Everything else stays on.
- Every circuit fully independent
- Faults isolated to one circuit
- Better for large homes
- Higher specification, higher cost
For most Cardiff homes, either option meets the regulations. We'll advise which suits your property and budget.
How long does it take?
A straightforward consumer unit swap on a standard Cardiff semi typically takes between half a day and a full day. You'll be without power for a few hours while the board is changed over. We plan the work to minimise the time you're off supply.
Larger properties, or jobs where earth bonding needs upgrading, can run into a second day. We'll confirm the programme before we start.
Building regs and NAPIT notification
Replacing a consumer unit is notifiable work under Part P of the Building Regulations in England and Wales. It can only be carried out legally by a competent person registered with an approved scheme. CMJ Electrical is NAPIT registered, so we self-certify the work directly. You don't need to separately apply to Cardiff Council.
When the job is done, we issue an Electrical Installation Certificate. Keep this safe. You'll need it if you sell your home, and your mortgage lender or insurer may ask for it.
Consumer unit upgrade costs in Cardiff
The cost depends on the number of circuits, whether earth bonding needs upgrading, whether you want an RCD or RCBO board, and any additional work needed. We don't quote over the phone without seeing the job.
We offer a free no-obligation survey. No call-out fee. You'll get a clear written price before any work starts.
Questions about consumer unit upgrades
Will my electricity be off all day?
You'll be off supply for the period we're swapping the boards, typically two to four hours. We restore power circuit by circuit as we complete testing. Most households in Cardiff manage fine on the day.
Do I need a new consumer unit if I'm getting a rewire?
Yes. A full rewire includes a new consumer unit as standard. If you're getting a full house rewire in Cardiff, the new board is part of the package.
My board has been flagged on an EICR. Does that mean it's dangerous?
It depends on the code. A C1 means immediate danger and the circuit should be taken out of use. A C2 means potentially dangerous and needs attention soon. A C3 is a recommendation only. We can advise on what the EICR codes mean for your property. See our EICR testing page for more detail on the coding system.
Related services
Areas we cover
Based in Cardiff CF3. Covering Cardiff and South East Wales.
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