Hot stoves don't represent a fire hazard as long as they remain in good working condition and are used with care. Repairing a chip or deep scratch in a glass cooktop isn't advisable because the integrity of the stove top has been jeopardized. No amount of glass stove top glue or other home remedies will safely restore a damaged stove top, but you may be able to buff out minor scratches.
Glass Top Stove Repair
Surface scratches in a glass stove top represent an aesthetic issue but not a safety issue. These blemishes can be remedied at little to no cost using household items like baking soda or specialty products like glass-safe metal polish or a glass scratch repair kit. Always be sure to use nonflammable products on your stove, even if the scratch isn't over a heating element.
Chips and cracks aren't so easily repaired, at least not safely. A deep scratch in a glass cooktop could expose the heating element and electrical components. There's no way to safely fix these deeper layers. The best option is to replace the cooktop altogether.
Do not continue to use the undamaged area of the stove. Doing so increases the likelihood of food and liquid falling into the cracked area, which could pose an electrical hazard and a possible kitchen fire, depending on how deep the gouge is. Play it safe and plan to replace the glass stove top as soon as possible.
Cost to Replace Glass Stove Top
Fortunately, replacing a damaged glass stove top doesn't necessarily mean you need to purchase an entirely new range. If you're happy with the performance of your stove and oven, you can remove the glass cooktop and install a new one or call an appliance technician to do it for you.
The cost to replace a glass stove top varies, but expect to pay several hundred dollars for this part alone at a site like Appliance Parts Pros. It may be economical to purchase a brand-new range, or you can consider going "parts shopping" at your local Habitat ReStore or even on Craigslist. Look for the same or similar stove model with a smooth glass top.
The glass does not contain any heating elements. It sits on top of round heating elements that transfer heat through the glass and to your cookware. Therefore, it doesn't matter if the rest of the stove doesn't work, since you'll just remove the glass top from the junk stove and use it to replace the cracked stove top.
Why Do Glass Stoves Crack?
You don't want to go to the trouble and expense of replacing a cracked stove top only to have the new one crack as well, so it's helpful to know why the glass cracked in the first place. Thermal shock is a major culprit, and it occurs when a hot pan is placed on a cold glass stove. At a molecular level, the glass needs time to expand in response to an increase in temperature. When there's a significant difference between the core temperature of the glass and the temperature that it's exposed to, the glass molecules don't react at the same rate and fall apart — or crack!
To prevent a glass stove top cracked from heat, avoid moving hot pots from an active burner to a cool burner or allowing pans to come out of the hot oven and rest on the glass stove top. Instead, place heat-resistant trivets or hot pads on the counter and allow hot pots and pans to cool down on these materials.