How to Preheat an Oven. Put food in a cold oven and your recipe will not turn out quite as planned. Preheat your oven to the desired temperature before baking for an evenly cooked meal. Put recipes in a cold oven only if specified in the recipe.
Search the oven for a preheat button or knob. Many modern ovens have electronic oven controls operated by pushing a keypad. Set the oven temperature called for in the recipe. Find the preheat button and press it. A red light will appear on the operating panel and a beep should sound when the oven is finished preheating. The preheating light turns off when the specified temperature is reached, but the oven light remains on.
Look at the settings found on the knobs of manual oven controls. Turn the knob to the temperature at which you plan to preheat. A light indicates the oven is preheating. Switch the knob to bake when the preheating light goes off.
Purchase an oven thermometer if you want to make sure the oven is preheating properly. Do not open the oven door during the preheat cycle or you will lose oven heat. Check the oven thermometer before baking to ensure the oven reaches the right baking temperature. Find oven thermometers online on the Improvements website or anywhere oven accessories are sold.
Preheat your oven for 15 to 20 minutes if you do not have a preheat function.