VESTEL VEA24026 Instructions D'utilisation Et D'installation page 42

This is especially true in the case of sugar/syrup mixtures which could
permanently pit the surface of the hob if left to burn on it.
If any of these products has melted on the ceramic surface, you should
remove it immediately (when the surface is still hot) by using a scraper to
avoid any permanent damage to the surface of the hob (available from the
s t o r e w h e r e y o u p u r c h a s e d t h i s a p p l i a n c e ) .
Do not put articles on the hob which can melt: i.e. plastic, aluminium foil,
sugar, sugar syrup mixtures etc.
Avoid using a knife or other sharp utensil as these may damage the ceramic
surface.
Do not use steel wool or an abrasive sponge which could scratch the surface
permanently.