"F24" is a Temperature sensor error. The following link explains:
http://www.fixya.com/support/r3608650-f24_error_codeThe temperature sensor, is located under the bottom front of the wash tub. It is a small square black plug between the heating element terminals. In many cases the connector plug comes loose and simply needs to be reconnected.
If the sensor is defective, a replacement can be purchased at any of the following websites:
searspartsdirect.com
pcappliancerepair.com
appliancepartspros.com
repairclinic.com
Prices vary between these sites, so shop and compare. If the model number is correct, the part number you need is 1404-000230. It is listed as item 6A in the parts listing at pcappliancerepair.com, but does not show an image of it. The average cost is about $10.
Each one of these washers comes with a technical data sheet inside.
To access, you will need to remove the lower toe panel under the door. The access screws are located under the bottom front edge of the panel. You may have to prop the two front fett of the washer up for better access ( a 2x4 works well for this). With the screws removed, the panel should drop down, then come off. If the tech sheet isn't directly behind the panel, it will be affixed to one of the interior cabinet walls. The tech sheet lists all error code definitions, troubleshooting data, diagnostics procedures and wiring diagrams. I mention the tech sheet because you may need it to troubleshoot this error code.
Although, the problem is usually attributed to the sensor, it could possibly be the heating element and/or connections. The tech sheet should list the steps necessary to isolate the problem.
If you have any questions about this repair, please post back and let me know. I hope this helps you.