The F5 fault code appears when the central control board registers an abnormal level of temperature sensor resistance. F11 occurs when there is no proper communication between the central control board and the motor control board. The latter is located at the washer’s bottom near the motor.
If you see the F5 code, the NTC temp sensor has failed. You can try this: unplug the machine and remove the lower front panel to get to the temp sensor (see the first image below). It is located in the middle part of the heating unit (located on the lower front part of the tub). Test the sensor with a volt- or ohm meter. Disconnect one wire and check the resistance with your meter. It should be 10-12Kohms. Check with the resistance chart in the second image below. If there is a serious deviation, have the sensor replaced. If the sensor is good, check the wiring harness. Check the TH2.1 and TH2.2 connectors, through which the sensor is plugged into the central control board, to ensure that they are not loose, damaged or rust. If the harness is ok, have your washer checked by a qualified technician. Not unlikely, the central control board is down.