How to Fix / Troubleshooting

Safety first: Turn off power at the breaker and allow the oven to cool before accessing the rear panel.

Check fan operation: In a convection mode, listen for the fan. If silent or humming without spinning, suspect the motor.
Access fan: Remove the rear panel of the oven (or the inner rear cover inside the cavity, depending on model) to expose the convection fan assembly.
Inspect blades: Look for food debris, foil, or grease buildup obstructing the fan. Clean thoroughly and ensure the fan spins freely by hand.
Test motor: Disconnect the motor and measure resistance. An open circuit indicates a failed motor. Also check for signs of overheating on the motor housing.
Check wiring and relay: Inspect the harness from the motor to the control board. If the motor is good but never receives power, the fan relay or triac on the main board may be defective.

Bosch oven shows E805 and fan-assisted modes do not work properly

Possible Causes