A cooker switch is a 45A double-pole isolator on its own circuit — not a 13A spur, and not something you take off a ring main. An electric cooker draws far more than a socket circuit is built for, which is why it gets its own cable, its own breaker and its own switch.
That's the whole reason the device exists: one switch that kills both live and neutral to a high-current appliance, within reach, without going to the consumer unit.
We sell these constantly at Villa Road, and the two questions are always the same — do I need the one with the socket, and can I use the existing cable. Here's both, plus the bits nobody asks about until it's too late.
1. Why 45A, and why double pole
A typical freestanding electric cooker or a built-in oven-and-hob pairing draws well beyond what a 13A plug or a 20A circuit can carry. So it goes on a dedicated circuit — usually a 32A or 45A breaker at the consumer unit, in cable sized to match.
Double pole means the switch breaks the live and the neutral. On a fixed appliance that somebody will one day pull out to clean behind, that matters: single-pole isolation leaves the neutral connected, and anyone working on it later has a live conductor they didn't expect.
This is not a place to improvise. A cooker switch is a safety device with a specific rating, and 45A is the standard for a reason.
The Knightsbridge CU8333 is a 45A double-pole cooker switch with a 13A socket, white, IP20, 230V, on a 7mm profile. The red rocker is the giveaway — that colour is the convention for a cooker isolator, and it's there so nobody mistakes it for a light switch.
2. With socket, or without?
This is the decision people ring us about.
The with-socket version gives you a 13A outlet in the same plate. Genuinely useful in a kitchen where worktop sockets are scarce — a kettle, a toaster, something that lives on the counter beside the hob.
The without-socket version is a plain isolator. Cleaner, smaller, and the right answer when there are already sockets nearby or the switch is going somewhere awkward.
Trade Tip: the 13A socket on a cooker switch is fed from the cooker circuit, not from the ring main. That's fine for a kettle, and it's the reason the socket exists — but it means a fault on something plugged into it trips the cooker circuit, taking the cooker with it. Don't run anything critical or permanent from it. It's a convenience outlet, not a spare ring socket.
For a commercial kitchen, a utility or a garage, the Knightsbridge MR8333N is the metal-clad version — 45A DP cooker switch and 13A switched socket, neons, powder-coated, heavy duty, 230V. Metal clad where a plastic plate would get knocked.
3. The connection unit at the other end
The switch is only half the job. Cable runs from the switch down behind the cooker to a cooker connection unit — the plate at skirting level with a clamp, where the appliance's own tail is terminated.
It exists so the cooker can be disconnected and pulled out without disturbing the fixed wiring.
The Knightsbridge CU8340 is a 45A cooker connection unit with a curved edge and concealed fitting, anti-microbial, certified to BS 5733, in thermoset resin. The SN8340 is the square-edge equivalent, IP20, 86mm wide, in packs of 5.
Fit the connection unit low and to one side — not directly behind the cooker where you can't reach it, and not so low it's in the kickboard.
4. Where the switch goes
Within reach of the cooker, but never directly above the hob. Reaching across a hot ring to switch something off is the exact situation the switch is supposed to prevent.
Standard practice is to one side, above worktop height, roughly 300mm horizontally clear of the hob edge and easily reached without leaning over anything hot.
It also needs to be reachable in a hurry. A cooker switch behind a wall unit or above a tall fridge is compliant on paper and useless in practice.
5. Cable — the question to ask before you buy anything
Cooker circuits are typically wired in 6mm² twin and earth, sometimes 10mm² for a larger appliance or a long run. The exact size depends on the load, the run length, the installation method and the protective device — which is why it's a calculation, not a lookup.
Trade Tip: if you're replacing a cooker with a more powerful one, check the existing cable and breaker before you buy the cooker, not after it's delivered. An older kitchen may have a 6mm² circuit that suited a modest cooker and is undersized for a big range. That's a rewire of the circuit, not a switch swap, and it's a much better conversation to have in a showroom than in a kitchen with an appliance on the floor.
6. Where DIY stops — and here it stops early
Swapping a like-for-like cooker switch on an existing, sound, correctly-isolated circuit is within reach of a competent DIYer. Isolate at the consumer unit, prove dead, photograph the terminals before anything comes loose, and check the cable is in good condition.
Everything else here is an electrician's job: installing a new cooker circuit, changing the cable size, changing the breaker, or moving the switch. Those are new-circuit works — notifiable under Part P in England and Wales, requiring testing and certification. Rules differ in Scotland.
This is a high-current circuit feeding a heating appliance. It's not the place to find out where the limits of your confidence are.
For lower-current fixed appliances, a 13A fused spur is the right device instead — see our guide to fused spurs.
Cooker switch quick-reference
| Question | Answer |
|---|---|
| What rating? | 45A, double pole |
| Which circuit? | Its own, from the consumer unit — never a ring main |
| With socket? | Only if you want a convenience outlet — it shares the cooker circuit |
| Where? | To one side of the hob, above worktop, easily reached |
| Cable? | Commonly 6mm², sometimes 10mm² — calculated, not assumed |
| At the cooker? | A 45A cooker connection unit at low level |
Expert Help in the West Midlands
We've been trading from Villa Road in Handsworth since 1975, and the counter is open to installers and homeowners alike.
If you're upgrading a cooker, bring the new appliance's rating plate details and a photo of your existing switch and consumer unit. That tells us in two minutes whether it's a straight swap or whether the circuit needs looking at first — which is a far better thing to know before the cooker arrives.
Browse the range in Cooker Switches.
Frequently asked questions
Can I use a 13A fused spur for a cooker?
No. An electric cooker needs a dedicated 45A circuit with a double-pole cooker switch. A 13A spur is for low-current fixed appliances like fans and boilers, and cannot carry a cooker's load.
Do I need the cooker switch with a socket?
Only if you want a convenience outlet beside the hob. It's fed from the cooker circuit, so anything plugged in shares that circuit — fine for a kettle, not for anything that must stay on.
How far from the hob should a cooker switch be?
To one side and above worktop level, so you never reach across a hot hob to use it — commonly around 300mm clear of the hob edge. It must also be reachable quickly, so not tucked behind a wall unit.