F1:-1 may appear on your Gemini oven range for various reasons, but the meaning is always the same. The error means that the display relay control board thinks your temperature on your upper double oven range is running away and getting too hot. To fix the error F1-1, check the wire harness between your oven sensor and your control board to make sure the wires are secure and the connections are good. Pull the oven out and remove the back panel on the oven to check the wires connections. If the connections and wires check good, disconnect the wire connection to the oven sensor and check the resistance of the sensor. The resistance should be 1100 ohm at standard room temperature. If the sensor is not good you need to replace it, and if the sensor checks within range replace the display control board.