Consumer unit and fuse board upgrades
Old fuse boards swapped for a modern RCD-protected consumer unit, tested and certificated.
In short
A consumer unit upgrade replaces the old fuse board with a modern metal-clad unit fitted with RCD or RCBO protection, so a fault or a cut cable trips the supply in milliseconds instead of relying on a rewireable fuse. It is the single biggest safety improvement most older houses can make. Since 2016 consumer units in domestic premises have had to be in a non-combustible enclosure, which is why the new one is steel rather than plastic. The changeover itself is usually a day, and every existing circuit is tested before the certificate is issued.
If your fuse board still has rewireable fuse carriers with fuse wire in them, or a row of plastic switches and no test button anywhere, it predates the protection modern regulations expect. It will still carry the load. What it will not do is disconnect fast enough to protect somebody who puts a nail through a cable or picks up a faulty appliance.
Signs your fuse board needs replacing
- Rewireable fuses with fuse wire rather than breakers that switch off
- A plastic consumer unit, particularly one under a wooden staircase
- No RCD, meaning no test button on the board at all
- Breakers that trip regularly, or one circuit that keeps taking the whole house out
- Signs of heat: browning, scorching or a smell of hot plastic around the board
- A board so full there is nowhere to add a circuit for a shower, hob or EV charger
What the job involves
Every property is different, but the shape of the work is usually the same. Here is how a typical consumer unit and fuse board upgrades job runs.
Look at what is there
The existing board, the incoming supply, the earthing and bonding, and the circuits themselves all get checked before anything is quoted. Whether an upgrade is straightforward or needs remedial work first depends on what is found here.
Agree the board and the day
You are told which unit is going in and how the circuits will be split across it, so a fault on one circuit does not take the whole house out. The supply is off for most of the day, so it is planned around you.
Isolate and change over
The supply is isolated, the old board comes off and the new unit goes on, with every circuit identified, terminated and labelled properly rather than guessed at.
Test every circuit
Continuity, insulation resistance, earth fault loop impedance and RCD operating times are all measured and recorded. This is where an existing fault on an old circuit tends to show up.
Certificate and hand over
You get an Electrical Installation Certificate with the test results on it, a labelled board, and a walk through of what each way does and how to test the RCD.
Want someone to take a look?
Call 07557 448945 or send a photo on WhatsApp and you will get a straight answer on what it needs.
Consumer unit and fuse board upgrades near you
S. Sparham Electrical covers Derbyshire and Nottinghamshire. Pick your area for local detail, or call 07557 448945 if you are not sure whether you are in range.
Frequently asked questions
How long does a consumer unit change take?
Most domestic changeovers are a single day. The power is off for the bulk of it, because every circuit has to be disconnected, re-terminated and then tested. If the testing finds a fault on an existing circuit, that has to be put right before the new board can be signed off, which can add time.
Do I legally have to upgrade my fuse board?
No. There is no law forcing you to replace a working fuse board in your own home. But replacing a consumer unit is notifiable work under Part P of the Building Regulations in England and Wales, so once you do it, it has to be either carried out by someone registered with a competent person scheme or notified to your local building control beforehand.
Why is the new consumer unit made of metal?
Since January 2016 consumer units in domestic premises have had to be in a non-combustible enclosure, after a run of fires that started inside plastic boards where a loose connection had been overheating. A steel enclosure contains it instead of feeding it.
What is the difference between RCD and RCBO?
An RCD protects a group of circuits at once, so a fault on any one of them takes the whole group off. RCBOs give each circuit its own protection, so a fault in the garden lighting leaves the freezer and the upstairs sockets running. RCBOs cost more and are generally worth it.
Will my old wiring pass on a new board?
Not always, and it is better to know. Old rubber or fabric insulated cable, lighting circuits with no earth, or damp getting into an outbuilding circuit will all show up in the testing. A new board makes those faults trip rather than hiding them, which is exactly the point, but it does mean some houses need remedial work first.
Who is doing the work
Before anyone works on your electrics it is worth knowing what they are trained to do. This is what Stephen Sparham holds.