Two glass top stoves broken, first, son was steaming a cowboy hat,ha, using a porcelin (sp) tea kettle, fused to top and as it cooled the top cracked. Second one broke when using corningware pan boiling eggs, again broke when pan fused to top & broke when cooling. Both these were used with medium to low heat. (I always used bleach to keep my tops white), Third was a glass top with burners above the glass top, and it lasted longest. All these were top of the line units. Loved to cook on them but I would be very cautious as to the pans I use.