Diagnosis
The bottom heating element is cycling incorrectly or the temperature sensor is providing faulty readings. The oven defaults to excessive bottom heat.
How to Fix It
Use the correct rack position. For convection baking, the wire rack must be in position 2 or 3. Never use position 1 (the lowest). This allows proper air circulation and reduces direct radiant heat from the bottom element.
If That Didn't Work
Manually adjust the temperature. Try setting the convection temperature 25°F (approx. 15°C) lower than your recipe states. Use a standalone oven thermometer on the rack to verify actual cavity temperature.
Heads Up
Avoid dark or non-stick pans. They absorb more heat from the bottom element. Use light-colored aluminum or steel baking sheets.