The diameter of the casserole's base should be equal to the size of the cooking zone. If the casserole is too small, the element may not sense the casserole and will not activate. Here´s an illustration of how to place the casserole on the correct cooking zone.
Another reason why a casserole may not work on induction is because the base of the casserole is convex. That happens due to a shock temperature:
Never clean a casserole under cold water when it is still hot. Let it always cool down.
Do not turn on the induction hob on full power. We advise to turn it on slowly (3/9 power) and build up the power slowly.
Induction cooktops produce very intense heat in a very short time. Our casseroles and pans heat up very quickly. Be careful with high temperatures and never leave your cookware unattended during use.
When using induction hobs, ensure that your hob and cookware are free from debris so as not to scratch the hob’s surface.
NEVER shuffle or drag pans and casseroles across the stove top during cooking as this may cause scratching. Always lift the pan or the casserole.