F13 is a dryer sensor fault. But a few thing can cause this.
Does it do this on wash or dry cycle only?
If on wash then you need to remove the top of the washer and there you will see the metal dryer chamber.
Towards the front of this is the dryer sensor, It will have 2 thin wires going to it. Check the wiring on there as sometimes the wires can break going to the sensor.
If the wires are fine then you need to test the NTC with a multimeter and see what reading you get. It should be about 20K ohms. If fauoty then it will need to be replaced. But if the sensor is fine and its still comming up F13 on wash then its going to be the control board.
But if the fault only shows up on the dryer cycle only then you need to remove the dryer condesner which sits under the metal dryer chamber on the top.
Clear out any fluff in there thats built up.
Then make sure the fan motor on the top is running and then retry it and see how it goes from there.
Check the above and see what you find. If you need anymore info just get back to me.