Two trays bake differently in the same oven

Describe the difference precisely: the upper tray browns too fast, one side of each pan remains pale, or everything takes longer than before. Include the rack positions, pan materials and whether the same recipe previously worked. Comparing unlike foods or very different pans can make the result harder to interpret.

Check the model manual for the recommended mode and rack arrangement for multiple trays. Thermador’s baking guidance emphasizes appropriate pan placement and a fully closed door. Avoid lining vents or the oven floor with foil unless the manual explicitly permits the intended use. Do not change calibration simply because one unusually crowded load baked unevenly.

If the familiar setup suddenly produces a repeatable new pattern, tell the technician whether fan sounds, preheating or the door have changed. Record actual cooking results rather than relying on one instant thermometer reading. An assessment can distinguish an operating setup issue from a heating, air-circulation or control concern; appearance alone does not identify a failed part.

Useful observations before you call

• Photograph the rack and pan arrangement while the oven is cool.
• Record the cooking mode, target setting and recipe timing.
• Mention whether the uneven result occurs with one tray as well as two.

Model-specific reference: Thermador owner support. Features and procedures vary; follow your appliance manual.