Bosch Range Error Code F121

F121 indicates that the touch key voltage on the control panel has been detected outside of acceptable limits, affecting all touch keys except CANCEL. The most common cause is contamination, such as grease or moisture residue, on the back side of the control glass between the display board and the glass surface. It can also be triggered by the oven vent discharging air behind the front manifold area, which deposits a film over time. Cleaning the glass is the recommended first step before replacing any components.

The F121 code disables the touch keypad, which means most control functions will not respond to input while the error is active. The CANCEL key remains functional. You should not attempt to force operation while the fault is present, and it is advisable to address the contamination issue before continuing regular use.

If the fix is simply cleaning the control glass with alcohol, the repair cost is minimal, typically just the cost of the cleaning supplies. If the display control board requires replacement, parts and labor costs can range from roughly $150 to $400 or more depending on the model and service rates in your area. Correcting a vent discharge issue is usually a no-cost adjustment made during the same service visit.

In many cases, yes. The first step is to clean the back side of the control glass with isopropyl alcohol to remove any grease or residue that may be interfering with the touch key voltage. You should also check that the oven vent outlet is not directing exhaust behind the front manifold toward the control panel. If cleaning resolves the issue and the error does not return, no parts or professional service are needed.

A power reset may temporarily clear the F121 code, but if the underlying contamination or vent discharge issue is not corrected, the error will likely return. To resolve it permanently, the back side of the control glass needs to be cleaned and the oven vent path should be inspected and corrected if needed.