Oven takes a very long time to preheat or never reaches the set temperature.

Safety first: Turn off power at the breaker before internal inspection.

• Check elements: Confirm that both bake and (if equipped) convection elements glow during preheat. If one does not, test and replace it.
• Verify sensor: Test the oven temperature sensor resistance at room temperature and replace if out of spec.
• Inspect door gasket: Look for tears, gaps, or hardened sections in the gasket that could leak heat. Replace if damaged.
• Use an oven thermometer: Place a reliable thermometer in the center of the oven and compare readings to the set temperature. Adjust calibration in the settings menu if needed.

Note: Overloading the oven with large, cold items can also slow preheat; test with an empty oven.