How to Tell if Your Oven is Accurate and Working Properly

How to Accurately Check Actual Oven Baking Temperature

Because the oven temperature rises and falls around the set temperature as the bake element or burner cycles on and off, you’ll need to record oven thermometer readings several times and calculate average oven temperature to accurately determine actual oven temperature. The more readings you take, the more accurate the average you calculate will be (oven repair technicians often take at least 5 readings).

Follow these steps to accurately find the actual oven temperature:

You’ll need an accurate oven thermometer for this task.

1. Put the oven thermometer on the middle rack and set the oven to 350 degrees.
2. Let the oven preheat and then wait at least 10 minutes more for the temperature to level out from the preheating temperature spike.
3. Check the oven thermometer reading by looking through the oven window and record the temperature on a sheet of paper.
4. Wait 10 minutes and record another oven thermometer reading. Continue taking several more readings every 10 minutes.
5. After recording the actual temperature readings from the oven thermometer, add the readings and divide by the number of readings you took to determine the actual oven temperature.

Knowing the actual oven temperature in your oven will help you determine if you need to calibrate the control and by how much.

Calibrating Oven Controls

How to Calibrate an Electronic Oven Control

The electronic oven control board (EOC) uses an oven temperature sensor probe to detect the actual temperature inside the oven cavity. When your actual average temperature reading inside the oven differs from the set temperature on the EOC, you can adjust or calibrate the EOC by creating an “offset” to compensate for the inaccuracy. Most EOC’s can be adjusted by an offset up to 35-degrees.

Refer to the owner’s manual for your oven for instructions for your model. Here’s an example from an owner’s manual that shows how to adjust the oven temperature in a common oven:

If you’re unable to complete this adjustment on your own, schedule oven repair service and we’ll send a service technician to your home to calibrate the EOC.

How to Calibrate an Oven Control Thermostat

An oven control thermostat uses a temperature sensor and potentiometer to cycle the bake element on and off to maintain the set oven temperature.

The difference between 350 degrees F and the average temperature you measured is the offset you'll use to calibrate (or adjust) the oven potentiometer.

For example, if the average was 330 degrees F, the offset is +20 degrees; if the average was 380 degrees F, the offset is -30 degrees.

Note: You can adjust most oven control thermostat by about 35 degrees in either direction. If the average temperature is off by more than 35 degrees, you’ll likely need to replace the oven control thermostat.

Here are instructions for adjusting the oven control thermostat in common types of ovens. (The exact steps vary by manufacturer, so check your owner's manual for instructions for your model.)

1. Pull off the temperature control knob.
2. On the back of the control knob you’ll find small adjustment screws and a pointer in a track. The back of the knob may be labeled Cooler at one end and Hotter at the other.
3. Loosen the screws just enough that you can move the pointer.
4. Move the pointer toward Cooler if the oven overcooks or Hotter if it undercooks. Each audible click adjusts set temperature about 10 degrees.
5. Tighten the screw and replace the knob.

Here’s an image to illustrate the temperature adjustment:

Repeat the process for checking the actual average temperature. Continue adjusting the oven control thermostat until actual average oven temperature matches the set temperature on the control.

If you’re unable to adjust the oven control thermostat on your own, schedule appliance repair service and we’ll send a Sears Home Services technician to your home to adjust the temperature or replace the oven control thermostat for you.

How to Fix Oven Heating Problems

When your oven isn’t heating properly and an oven control adjustment won’t fix the problem, a faulty oven temperature sensor or faulty control could be causing the problem.

If your oven uses an electronic oven control, unplug the range and test the oven temperature sensor using the procedure shown in this video:

(This video shows how to test the oven temperature sensor when the control is displaying an F30 or F31 error code that indicates a failed oven temperature sensor.)

At room temperature, your oven temperature sensor should measure around 1080 ohms of resistance.

Here’s a temperature sensor resistance chart that technicians use to check oven temperature sensor accuracy:

If the actual resistance that you measure through the oven temperature sensor is off by more than 100 ohms, you’ll likely need to replace the temperature sensor.

Here’s a video that shows how to replace an oven temperature sensor:

If resistance through the oven temperature sensor circuit is accurate, you’ll likely need to replace the EOC.

If your oven uses a control thermostat, you’ll likely need to replace that part to fix an oven heating problem that can’t be fixed by calibrating the control.

When you need help resolving an oven heating problem, schedule oven repair service and we’ll send a Sears Home Services technician to your home to fix the problem.

Understanding what causes oven heating problems and learning how to fix them will help you keep your oven heating properly so your baked goods turn out perfectly every time.