The F3-E2 error code means that the heated well above the setting the tempature was set at. The usual reason the oven would over heat by so much is a defective oven tempature sensor and the sensor would need to be tested to see if is the problem to test the sensor it would need to disconnected from the wiring to it and measure the amount of ohms of resistiance AT ROOM TEMPATURE when the oven is off and cool. At room temp. the the meter used to check the sensor should display between 1060-1100 ohms,if the number is vastly different that 1060-1100 at room tempature the sensor is defiently bad and should be replaced. This is what the sensor looks like
it will be inside of the oven chamber and again to properly check it the wiring should be unplugged and the meter leads should be placed into the plug at the end of the sensor to measure the ohms.
If after checking the sensor if its within the range of 1060-1100 ohms at room tempature the problem is going to be the control board.
I hope i have been able to help ya fix your oven,