This is the normal design of ovens and is factored into how recipes are created and used. The amount the oven will cycle higher or lower than the set temperature will vary and each individual model can be different. Temperatures can vary by + 30 degrees to – 30 degrees in most cases for a total swing of 60 degrees.
Woolsey says you shouldn't worry too much if your oven is off by 20 or so degrees, a range in which you can either tweak your cooking or calibrate the appliance. Once you start getting into 30-, 40- or 50-degree territory, though, you may want to consider calling a technician rather than calibrating the oven.
Understanding Expected Oven Temperature Fluctuation
The Oven temperature fluctuation varies by model and each individual Oven can be different. The temperature range can vary by + 30 degrees and – 30 degrees Fahrenheit as the oven cycles on and off for a total temperature fluctuation of 60 degrees.
Temperature Adjustments: Reduce the temperature by about 25 degrees Fahrenheit (about 15 degrees Celsius) when using a convection oven compared to a conventional oven. This is because convection ovens circulate hot air, which cooks food faster and more evenly.
Temperature Sensor: If the oven temperature is inaccurate, a faulty temperature sensor can be the cause. To troubleshoot this issue, check the wiring connections of the temperature sensor and test the sensor with a multimeter to determine if it is functioning correctly.
When your oven is heating but not reaching the set temperature, there may be an issue with the temperature settings, temperature sensor or calibration. The solution to your oven's heating problems could be checking to make sure your oven is set to the proper unit of measurement.
Your oven may need to be calibrated if your food is coming out under or over cooked. You can test it by preheating it to 350° F with an oven thermometer centered on the middle rack. If it reads 15° F higher or lower than it should when it reaches the 350° F level, it may need calibration.
Possible causes for a malfunction in an electric oven include electrical supply disruptions, broken heating elements, faulty temperature sensors and a malfunctioning control panel. If your electric oven isn't heating up, first check your circuit breaker for a blown fuse.
Because convection cooks food faster, common advice is to reduce the temperature by 25°F and expect foods to be done about 25 percent sooner. Depending on your oven, it may default to a lower temperature when using convection, but you can override that function.
Reduce the original baking temperature by 25°F.
For example, if your recipe calls for baking the food in a 375°F oven, set the dial to 350°F. If it calls for 400°F, set it to 375°F. What about 450°F? You got it, 425°F is your convection oven temperature.
Your Temperature Naturally Fluctuates
An individual's core body temperature typically changes by about 1 °C (1.8 °F) between its highest and lowest points each day. Anything outside of that range indicates that something is challenging your body and preventing it from adjusting.
To test the oven: Hang an oven thermometer in the center of the middle rack and preheat the oven to 350˚F (176.67˚C). Allow the oven to preheat for at least 20 minutes and take a temperature reading. This will tell you if the oven is even reaching the desired temperature from the beginning.
Your oven thermostat is the oven part which regulates the temperature. If the thermostat is broken, it will no longer be able to keep the temperature at a stable level and will cause fluctuation. This most often leads to burnt food, but can also lead to undercooked (and potentially dangerous) food.
Since all ovens cycle on and off to maintain temperature, even the best models will periodically deviate from the desired target by at least a few degrees throughout cooking […] On top of this,” they say, “we've found that ovens set to the same temperature can vary by as much as 90 degrees.”
In fact, your oven's thermometer could be off by up to 50 degrees, which makes a huge difference when cooking and baking delicate recipes at home. The biggest reason for this inaccuracy is the thermometer's placement inside of the oven.
Auto Recipe™ Conversion is used in Convection Bake and Convection Roast*. When the oven is set for Auto Recipe™ Conversion you may see CON appear shortly after setting the temperature and then the oven will automatically be set for 25 degrees less than the temperature entered.
Too Many Dishes Can Hinder Performance – While you can cook several dishes at once in a convection oven, if you overcrowd the oven or block the fan, the oven won't work as efficiently as it should. It could take much longer for your food to cook.
There are a few possible reasons why an oven isn't distributing heat evenly, including restricted airflow, improper oven calibration, overcrowded racks, a broken heating element, a malfunctioning temperature sensor or simple user error like opening the oven door too often during the baking process.
If you notice that your electric oven isn't heating up to the correct temperature and food comes out under-cooked, this many be caused by a defective electric oven thermostat. Thermostats measure the temperature inside the oven cavity, switching the electric element on and off to maintain the desired temperature.
When using convection, the temperature and time displayed on the oven may be different than what was entered and this is normal. The convection conversion feature is a function that converts a standard thermal bake cook time and temperature into an ideal cook time and temperature for convection cooking.
A convection oven cooks by blowing hot air all around the food with a fan with a vent allowing the air to escape. If the foil blocks or gets too close to the fan or vent, the foil could get so hot that it ends up catching fire.
Issues with the oven temperature sensor, thermostat, heating elements, gas igniter, electronic control board, or door hinges can all contribute to temperature inconsistencies, and identifying and replacing faulty components is key to restoring proper oven function.
Longer Cooking Times: If you find that your food is taking longer to cook than usual, it could be an indication that the temperature sensor isn't working properly. This can result in the oven not heating to the desired temperature, causing the food to take longer to cook.
If the oven thermometer shows a reading that is above or below 350℉ by 15 degrees or more, you will need to calibrate your oven.