Bosch Oven Error Code F121

F121 on a Bosch oven means the control system has detected a stuck keyboard key, or that the display head or keyboard assembly is malfunctioning. The oven monitors each control panel key for normal signal behavior, and F121 is triggered when a key appears to be continuously active or when the keyboard sends an invalid signal. The fault can originate from a physically stuck key, a bad connection between the display head and keyboard, or a failed component in either the keyboard or display head.

It is not recommended to continue using the oven while F121 is active. A stuck key condition or faulty keyboard signal can cause unpredictable control behavior, and the oven may not respond correctly to user inputs. Power the oven off until the fault is diagnosed and resolved.

Repair costs vary depending on the root cause. If the fix is simply reseating a loose connector, costs are minimal and limited to a service call fee, typically in the range of $75 to $150. Replacing the keyboard membrane or display head adds parts costs, which can bring the total repair into the $150 to $400 range depending on the specific model and labor rates in your area.

Some causes of F121 are DIY-friendly. Start by unplugging the oven and checking the connections at the P5 and J1 connectors between the display head and the keyboard. Inspect the keypad for any keys that feel stuck or show signs of contamination, and clean the surface carefully. If connections and the keypad surface appear normal, the repair likely requires replacing the keyboard membrane or display head, which involves working inside the control panel and may be better suited to a qualified technician.

A reset, such as cutting power to the oven at the breaker for a few minutes, may temporarily clear F121, but the code will return if the underlying problem is not corrected. If the fault is caused by a loose connection, debris under a key, or a failing component, those issues must be addressed directly. A reset alone is not a repair.