Modern metallic oven
The Easy Trick To Speeding Up Your Oven's Preheat
To speed up the process of preheating your oven, simply turn the broiler on for three to five minutes before setting the oven's temperature.
According to a test run by First For Women, running the broiler first for four minutes allowed them to preheat a 400-degree Fahrenheit oven in just 9 minutes instead of 20.
This is because turning on the broiler "can get your oven hot almost immediately, which helps you heat the entire appliance to your desired temperature," per East Coast Appliance.
To test this out for yourself, use a separate oven thermometer set away from the broiler to ensure that your oven has reached the correct temperature.