Before we start: This guide is for identification only. It will help you understand what’s behind your fuse board so you can have an informed conversation with an electrician — it is not a DIY instruction manual. Working inside a consumer unit is dangerous: live terminals, no room to work, and a genuine risk of electric shock or fire. If in doubt, stop reading and book an electrician. You should also never attempt to install, alter, or rewire anything yourself — in England and Wales that work is covered by Part P of the Building Regulations and must be signed off by a qualified electrician.
What Type of Breaker Do I Have?
If you’re renting, buying, or renovating an older UK home, the electrical setup can feel like a mystery. Maybe your landlord says “the electrics are fine,” or the estate agent shrugs when you ask about the fuse box. But when you want to install an electric cooker — or buy a plug-in one — the answer to “what type of breaker do I have?” decides everything.
Here’s the good news: you don’t need to be an electrician to identify what you’ve got. You need to know four things: the type of protection (fuse wire, MCB, RCD or RCBO), the cable sizes feeding your cooker point, the era of the installation, and whether the work meets the current standard. Let’s go through each.
Check Your Consumer Unit: Fuse Wire, MCB, RCD or RCBO
Open the consumer unit (the “fuse box”) — just the door, not the cover — and look at the devices protecting each circuit. You’ll see one of four things:
| Device | What it looks like | Era | What it means for you |
|---|---|---|---|
| Rewireable fuse (fuse wire) | Porcelain or black plastic carrier with a wire across two screws; a small window may show a blackened wire | Pre-1970s, still found in old boards | Oldest setup. Blows instead of tripping; slow to react to faults. If you have these and want a new cooker circuit, budget for a consumer unit upgrade. |
| MCB (miniature circuit breaker) | Small plastic switch, labelled with a letter + number (e.g. B16, B32, C32), coloured lever (usually black or grey) | 1970s–present | Modern circuit protection for overloads and short circuits. The number is the rated current in amps — a B32 feeds a 32A cooker circuit; a B16 feeds sockets or lights. |
| RCD (residual current device) | Wider switch with a “T” (test) button, labelled 30mA, sometimes with “RCD” printed on it | 1990s–present | Protects against electric shock. A 30mA RCD is the standard for sockets and cookers. If it lacks a test button, it’s not an RCD. |
| RCBO | One module that combines MCB + RCD: has both a current rating (B16/B32) and a test button | 2010s–present | The best of both: per-circuit shock + overload protection. Modern boards often have all-RCBO setups. |
How to read the labels: the letter tells you the trip curve (B = standard domestic; C = for appliances with a high start-up surge, like some ovens and hobs) and the number is the amp rating. A B32 or C32 on its own circuit, feeding a wall-mounted cooker switch, is the classic 32-amp cooker circuit setup.
2. What Cable Feeds the Cooker?
Cable size is the real limit on what you can run. In UK domestic wiring you’ll mostly see twin-and-earth cable (flat grey or white, two insulated cores + bare earth). The size that matters is the cross-sectional area of the copper, in mm²:
| Cable size | Typically feeds | Max circuit rating |
|---|---|---|
| 1.5mm² | Lighting circuits | 6A–10A |
| 2.5mm² | Socket ring/radial mains (your plug sockets) | 20A–32A (ring) |
| 4mm² | Showers, small fixed appliances | 20A–32A |
| 6mm² | Cookers, hobs, some showers | 32A |
| 10mm² | Large cookers, electric vehicle chargers | 40A–45A |
The golden rule for cookers: a standard electric cooker or induction hob needs its own circuit — typically 6mm² cable on a 32A breaker (10mm²/45A for larger models), feeding a cooker switch on the wall. If your cooker point is fed by the same 2.5mm² cable as your sockets, it is not a dedicated cooker circuit — which is exactly the situation this site exists to solve. A 2.5kW+ built-in oven on a socket circuit will trip the breaker when the elements kick in.
Only see the cable where it enters the consumer unit or behind the cooker switch? The cable size is printed on the grey sheath (e.g. “6183Y 2.5mm²”) — or an electrician can measure the copper for you in seconds.
3. Which Era Is Your Installation?
UK wiring has gone through distinct eras. Recognising yours tells you how likely it is to pass an inspection and what an upgrade would involve:
| Era | Signs | Standard |
|---|---|---|
| Pre-1960s | Wooden or metal fuse board, fuse wire, rubber-insulated or lead-sheathed cable | Pre-BS 7671 — needs a full rewire for new work |
| 1960s–1980s | Plastic consumer unit, fuse wire or early MCBs, PVC cable, red/black core colours | Old but often serviceable; new circuits may still be added |
| 1980s–2000s | MCBs, plastic enclosure, red/black cores, no RCD or one covering everything | 16th Edition era — an RCD check is worth doing |
| 2004–present | Brown/blue core colours (new work), metal or plastic enclosure | 17th/18th Edition — modern standard |
Since 2016, new consumer units in the UK must be in a non-combustible (metal) enclosure. So a plastic board isn’t automatically a problem, but a brand-new metal board is a strong signal your installation is recent and up to standard. If you still have fuse wire and rubber cable, treat any major appliance purchase as a “get a survey first” situation.
4. The Cooker Switch and the 13A Question
Find the wall switch that controls your cooker: a proper cooker setup has a 45A double-pole switch (often with a neon indicator) or a 32A DP switch, mounted at worktop height, fed by its own circuit. No cooker switch at all usually means no cooker circuit — the flat was never wired for one.
And that’s where the 13A angle comes in: if your home has no cooker circuit (or you don’t want to pay £300–£600 to have one installed), a 13-amp plug-in cooker — a mini oven, countertop cooker, or portable induction hob running off a standard socket — is the practical workaround. They’re designed to stay under the ~3,000W limit of a UK ring main. You can see our current picks in the freestanding 13A cooker guide and the mini oven roundup.
When to Stop Guessing and Call an Electrician
Book a qualified electrician (check they’re registered with a Part P scheme like NICEIC or NAPIT) if:
- You have fuse wire, rubber cable, or a wooden fuse board and want to add any fixed appliance
- You’re buying a built-in cooker or induction hob and aren’t sure the circuit exists
- Breakers trip regularly, the RCD won’t reset, or you can smell burning from the consumer unit
- Any DIY electrical work has been done before you moved in — unverified work is a common rental hazard
For the specific question of whether your flat already has a 32-amp cooker circuit, we’ve got a dedicated step-by-step: How Do I Know If My Kitchen Has a 32-Amp Cooker Circuit?. And if you’re weighing up whether to rewire or go plug-in, our installation cost breakdown gives you real numbers to compare.
The Bottom Line
Identifying your home’s electrical setup comes down to four quick checks: the breaker type (fuse wire, MCB, RCD or RCBO), the cable size feeding the cooker point, the era of the installation, and whether a proper cooker switch exists. None of this requires touching a live terminal — just looking. What you find determines whether a built-in cooker is a £300 install job, a £600 rewire job, or a sign that a 13A plug-in cooker is the smart move. When in doubt, get an electrician to do a quick inspection — it’s a lot cheaper than a fire.