Does a cooker need its own circuit?

This question has a clean technical answer that gets muddled because kitchens contain several things all called a cooker. A small tabletop oven with a plug is not the same electrical proposition as a freestanding range with four zones and a double oven. The dividing line is the total connected load on the rating plate against what a standard socket circuit can deliver, and once you are above it the installation stops being something you can do anything about yourself.

Safety

What you'll need

• The appliance's total rated load in kW, from its rating plate or manual
• The installation manual, which states the required supply
• A qualified electrician, for anything hard-wired

Step by step

1. Read the total rated load from the rating plate or the manual.Not the oven alone and not one hob zone — the total connected load with everything running. A double oven with an induction hob can be 7 to 11kW. The installation manual states the supply the manufacturer requires and that is the authoritative figure.
2. Apply the plug test.If the appliance is supplied with a fitted 13A plug, the manufacturer has designed it for an ordinary socket and its load is under 3kW. Many single built-in ovens, microwaves and compact ovens fall here and need no special provision beyond an accessible socket.
3. Treat anything without a plug as a dedicated circuit job.A cooker supplied with bare tails and a terminal block is intended to be hard-wired to a dedicated circuit through a cooker control unit or a cooker connection unit. There is no adaptor solution and there is no version of this that uses a socket.
4. Understand what a dedicated cooker circuit is.Its own cable run from its own breaker in the consumer unit, sized for the load, to a cooker control unit — a switch, sometimes with a socket, mounted to the side of and above the appliance rather than directly over it. From there a cable runs to a connection unit behind the appliance. Typical circuits are 32A, with larger installations sized accordingly.
5. Know why diversity means the circuit can be smaller than the total load.Electricians apply a diversity allowance because not every element of a cooker runs at full power simultaneously — thermostats cycle and it is unusual to have every zone and both ovens at maximum. That calculation is why an 11kW cooker does not need a 48A circuit. It is also why it is a calculation for a qualified person rather than a rule of thumb.
6. Check the existing circuit before buying a replacement cooker.A house wired for an older, lower-rated cooker may not have a circuit adequate for a modern induction hob and double oven. Establish what is there before ordering, because discovering it on delivery day is expensive and the delivery team will not install it.
7. Have induction hobs assessed specifically.Induction hobs draw heavily and quickly, and several models need a dedicated supply of their own separate from the oven, or a specific connection arrangement. The installation manual states it and it should be checked before purchase rather than after.
8. Have the work done by a registered competent person.In England and Wales a new circuit in a kitchen is notifiable under Part P, and the practical route is a registered electrician who self-certifies and issues the certificate. Scotland and Northern Ireland have equivalent requirements. Keep the certificate — it is asked for at sale.
9. Never improvise a connection.No adaptors, no extension leads, no wiring a hard-wired cooker to a plug, and no connecting two appliances to one cooker outlet unless an electrician has confirmed the circuit supports it. These are among the most serious electrical mistakes made in a domestic kitchen.
10. Keep the isolation switch accessible.The cooker control unit is the means of isolating the appliance in an emergency and for maintenance. It must be reachable without leaning over the hob, which is why it is mounted to the side rather than directly above.

Tips

• The installation manual is the authority. It states the required supply, and it is what an electrician will ask for.
• Check the existing circuit before you order a new cooker, not after. It is the most common expensive surprise in a kitchen appliance purchase.
• Keep the electrical certificate for any cooker circuit work with your house paperwork. It is routinely requested during a sale.
• A single built-in oven under 3kW with a fitted plug genuinely does just need a socket — but it needs one that stays accessible after the oven is installed.

Common mistakes

• Assuming an existing cooker point suits any replacement — A circuit sized for a 1990s cooker may not support a modern induction hob and double oven. The rating plate on the new appliance and the existing circuit have to be compared before purchase.
• Connecting a hard-wired cooker via a plug and socket — A 13A socket cannot carry the load, and a plug is not the designed means of connection or isolation. This is a fire risk and it will fail any inspection.
• Doing the work without notification — A new kitchen circuit is notifiable work. An unnotified alteration causes problems at sale, can affect insurance, and leaves nobody accountable for whether it was done correctly.

Questions people ask