How do I know if existing fuse and cable sufficient for replacement oven?

If you have a 13 Amp Spur that will be your limit unless you are willing to have alterations to your wiring. KiloWatts / Volts = Amps Cable Amps > Breaker/Fuse Amps > Oven Amps - You can find the ratings for cable in 18th edition using the cable calculations. - Breaker/Fuse ratings are on them. - Oven will have a Wattage if not Amps. I’d advice you have an electrician fit and test the oven. If you want to calculate yourself for fun or any other reason, google the cable you have and look for a pdf of the 18th edition wiring regs or an NICEIC crib sheet for cables ratings. Checking the Amps of the Oven is equal to or lower than that of the breaker/fuse is the essential part as the cable ‘should’ be correctly sized to the breaker/fuse. Typical consumptions Double Ovens 5-8kW (20-32A) Single Ovens 2.5-5kW (10A-20A)

Hello, You are indeed limited by the 13 A fuse, and associated wiring. Consult the manufacturer’s spec for installation guidance. There you will find the cable type, size, OCPD rating and connection method given by them. Good luck, Carl.

Short answer, you are limited to 3000Watts which is 13amps, I would ignore at least two of the answers above.

32amp is sufficent. You won't need more than that and you definitely don't need to derate it as some people might suggest. Typically 6mm twin and earth is used to connect ovens or cookers. If you buying a new one consult the installation instructions though.

There will be in the oven a plate telling you the ratings for the oven. It’s usually in the inside of the door. A silver sticker sometimes. It will tell you the rating of the oven. Normal ovens are about 4 amps or so and should be fit with heat resistant flex. Probably best getting someone who knows how to, to do the job.