Symptoms
- Baked goods consistently burn on the outside before the inside cooks
- Food takes much longer than a recipe suggests
- An oven thermometer reads differently than the display setting
- Preheat indicator beeps but oven isn't actually at temperature yet
Likely causes
- CommonOven temperature calibration drifted off over timeMost ovens allow a calibration offset adjustment to correct gradual drift from the true temperature.
- CommonFailing oven temperature sensor giving inaccurate readingsA sensor reading incorrectly causes the control board to over- or under-power the elements.
- PossibleOven door not sealing properly, letting heat escapeA worn door gasket lets heat escape, making the oven run cooler than its setting despite the element working correctly.
- PossiblePreheat indicator beeping before oven is actually at temperatureSome ovens signal preheat done a bit early, before actually reaching full temperature, which can be misread as inaccuracy.
- Less commonFaulty control board misreading sensor inputA board fault can cause inaccurate temperature regulation even with a good sensor.
What to do
- Place an accurate oven thermometer in the center of the oven and let it preheat fully to a set temperature like 350F.
- Compare the thermometer's reading to the set temperature after the oven signals it's ready, waiting an extra 10–15 minutes for full stabilization.
- Check your owner's manual for a temperature calibration/offset setting, which is often accessed through a button combination.
- Adjust the calibration offset in small increments (10–25 degrees) based on the thermometer difference, then retest.
- Inspect the door gasket for gaps, tears, or looseness that could let heat escape.
- Close the door on a piece of paper at multiple points around the seal; if it pulls out easily, the gasket may need replacing.
- If calibration adjustment doesn't fix a large or inconsistent discrepancy, have a technician test the temperature sensor.
Tools and parts
- Oven thermometer
Oven door gasketSearch: “oven door seal gasket replacement”
Oven temperature sensorSearch: “oven temperature sensor replacement”
When to call a pro
If calibration adjustments don't correct a significant or inconsistent temperature discrepancy, have a technician test the sensor and control board.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.