We recently bought an 8-yr old home with appliances and the previous owners did not leave any manuals behind. We are first-time home/appliance owners. All of a sudden, our display has stopped beeping as we change the temperature on the display to start preheating the oven. Additionally, the oven became superheated, almost to the point of catching our food on fire within minutes of putting it in the oven! Both the top and bottom of what we were baking was black! It also smelled like a gas leak in the room (keeping in mind this is an electric range, we can only attribute this to the silicone? oven liner which instead of being black looked more a blue and white when we pulled it out). Also, it is getting hot enough that it has partially melted our oven glove. Please help. Thank you.