Problems with ignition can put a stove or cooktop out of commission for days. Gas stoves utilize a combustion reaction to generate heat, and if a knob or spark wire is even remotely damaged, the stove or cooktop will cease to work properly. Most of the time, when a spark wire is damaged, a component, known as the ignition box will need to be professionally replaced. If your appliance fails to turn on or heat at all, you should definitely contact a stove repair professional at your earliest convenience.