Oven heats but does not reach the set temperature or takes excessively long to preheat.

Safety first: Turn off power before testing internal components. Use heat-resistant gloves when working near a hot oven.

• Verify with an oven thermometer: Place an accurate oven thermometer in the center of the cavity and compare actual temperature to the set temperature.
• Inspect elements: Look for cold spots or uneven glow on elements during heating. Replace any element that does not heat uniformly.
• Check door gasket: Inspect the rubber door seal for gaps, tears, or compression. Close the door on a sheet of paper around the perimeter; if it pulls out easily, the seal may be worn. Replace the door gasket if needed.
• Test temperature sensor: Measure sensor resistance at room temperature and compare to spec. A sensor reading too low resistance will cause underheating. Replace if out of range.
• Calibration: Some Gorenje models allow temperature offset adjustment in settings. Refer to the user manual to adjust calibration if the oven is consistently off by a small amount.