The "F1" error code flashes when the control board detects an out of range pressure signal.
The pressure hose connection from the tub to the machine control board could be pinched, kinked or restricted.
If "F1" repeats numerous times after POWER is pressed and the pressure hose is NOT pinched or kinked, replace the machine/motor control board assembly.
The F1 error code indicates a primary control board failure. To repair this problem, the control board will most likely need to be replaced. First, I would recommend that you check the pressure hose.
Always unplug or de-energize electrical equipment before removing covers or attempting service. Be careful and wear appropriate hand protection when working around sharp metal parts.
Make sure it is attached well at the MCE (Machine/Motor Control Electronics). You can disconnect the pressure hose from the MCE and blow through it, there should be no resistance. Hook the hose back up and try running the washer. If the F1 reappears, replace the MCE.
The image below shows the procedure for replacing the control board in this washer. If you are able to safely access the control board, you may be able to complete this repair yourself. You can order the new control board from Sears Parts Direct please click here;
Sears Parts Direct
If you require further assistance please resubmit question with details of the checks you have made. I will be looking forward to helping you again in the near future.