Expert electrical advice from our NICEIC registered team
Written by Tim, NICEIC registered with 18+ years experience in Poole & Dorset · 5-star Google reviews · Same-day fixed quote, no obligation.
An old fuse box doesn’t have to be replaced just because it’s old. It has to be safe. It’s time for a new one when it has rewirable fuses with no RCD protection, it’s damaged, scorched or buzzing, a single fault keeps taking out half the house, or you’re adding a new circuit and there’s no room left. A modern board puts an RCBO on every circuit, so one fault only switches off the circuit that has it.
Our RCBO consumer units start from £450 fitted. See our fuse box and consumer unit upgrades, or ring Tim on 07809 680068 if yours is worrying you.
Take the cover off the fuse box (or have a look through the door) and check for these:
If you rent the property out, the EICR decides it. A board with no RCD protection on the sockets is often coded on an EICR, and a C2 code has to be fixed within 28 days. Our EICR cost guide explains the codes.
There are three types of switch on a modern board, and it helps to know what each one does.
| Device | What it protects against | How much it switches off |
|---|---|---|
| MCB (miniature circuit breaker) | Too much current on a circuit: overloads and short circuits | One circuit |
| RCD (residual current device) | Current leaking to earth, which is what happens when someone gets a shock | Every circuit it covers, often half the board |
| RCBO | Both of the above in one device | One circuit |
An RCD compares the current going out on the live wire with the current coming back on the neutral. If some of it is leaking to earth, through a faulty kettle or through a person, it switches off in a fraction of a second. On a home board it’s rated at 30mA, which is low enough to stop a shock from being fatal.
The catch is on older boards from the 1990s and 2000s. These are usually split-load boards, with one or two RCDs, each covering a bank of circuits. One faulty appliance trips the RCD, and every circuit on that side goes off with it. That’s how you end up with the fridge freezer off overnight because the outside light got wet.
An RCBO is an RCD and an MCB in one device, and every circuit gets its own. A fault on the kitchen sockets trips the kitchen sockets and nothing else. The lights stay on, the freezer stays on, and you can see straight away which circuit has the problem.
Every consumer unit we fit has an RCBO on every circuit.
A board with RCD protection is safe. RCBOs are better to live with because one fault doesn’t take out half the house, and that’s why we fit them as standard. If your split-load board is in good condition and you’re not adding anything, you don’t have to change it. If it keeps tripping, our fuse box keeps tripping guide goes through the checks to make first.
Since 1 January 2016, any new consumer unit fitted in a home has had to have a non-combustible case, which in practice means metal. The rule came in because of fires that started in plastic boards, often from loose connections.
An existing plastic board doesn’t have to come out because of the rule. It only matters when the board is being replaced anyway, or it’s damaged. Every board we fit is metal.
Two optional extras are worth knowing about when you’re replacing a board:
| Board | Price fitted |
|---|---|
| 6-way RCBO board (small flat or 1-bed) | From £450 |
| 10-way RCBO board (typical 2 to 3 bed home) | From £550 |
| 14-way RCBO board (4 to 5 bed or extended home) | From £750 |
| Add surge protection (SPD) | + £95 |
| Add arc fault detection (AFDD), per circuit | + £65 |
That includes a metal RCBO board, testing every circuit, the NICEIC Electrical Installation Certificate and Building Control notification. Our consumer unit cost guide explains what changes the price, and everything we charge is on the prices page.
Worried about an old fuse box? Send Tim a photo of it on WhatsApp or call 07809 680068. We’ll tell you straight whether it needs replacing. We cover Poole, Bournemouth, Christchurch and Wimborne.
No. There's no law that says a homeowner has to replace an old fuse box. It has to be safe, though, and landlords need a satisfactory EICR. An old board with no RCD protection often gets coded on an EICR, and that can mean replacing it.
The usual signs are rewirable fuses with wire in them, a wooden back board, no RCD test button anywhere on the board, a plastic board that is cracked or scorched, a board that buzzes or feels warm, or one fault knocking out half the house. Adding an EV charger, an electric shower or a new circuit to a full board is another common reason.
An RCD protects you from electric shock by switching off when current leaks to earth, but on most older boards one RCD covers a whole bank of circuits. An RCBO does the same job as an RCD and a circuit breaker combined, for one circuit only. With RCBOs, a fault on one circuit only switches that circuit off.
No. Since 1 January 2016, new consumer units fitted in homes have had to be non-combustible, which in practice means metal. Existing plastic boards don't have to come out because of that rule, but if one is damaged or being replaced anyway, the new one will be metal.
Our RCBO consumer units start from £450 for a 6-way board, £550 for a 10-way board for a typical 2 to 3 bed home, and £750 for a 14-way board. Surge protection adds £95. That includes testing, the NICEIC certificate and Building Control notification.
Tim and his team are happy to answer questions or provide a free, no-obligation quote. 5-star Google reviews and counting.
Tim and his NICEIC-registered team are here to help. Message us on WhatsApp or call 07809 680068 for a free, no-obligation quote.
