The F02 error code on a Kenmore HE3 washer indicates that the control detects a long drain time. This can be caused by excessive suds in the tub, a restriction or clog in the drain system or by a number of other component failures.
If the washer did not drain, check for excessive suds in the tub. After the suds dissipate, you can normally run a rinse/drain and spin cycle. Causes for excessive suds include not using HE (High Efficiency) detergent or using too much detergent (even if it is HE type).
If the washer will not drain and you do not detect excessive suds, you could have a clog in the drain system. Check the drain hose and the washer drain. You may need to manually unlock the washer door and then pull the large item filter on the pump to check for a clog. To manually unlock the washer door,
unplug the washer
to disconnect electrical power and remove the bottom front service panel as shown in the top of the image below. Carefully reach up along the inside of the front panel and pull down on the tab that is under the door lock mechanism until it clicks. This will unlock the washer door. Open the door and manually drain the water out of the washer with a wet/dry shop vacuum. Once the washer is drained, arrange some towels to catch residual water that will drain out and remove the large item filter as shown in the image below. Check for a clog or restriction that could be preventing the washer from draining properly.
If you find no clog or restriction in the drain system, you may have a bad drain pump that needs to be replaced. A problem with the electronic control board could also prevent the washer from draining.
If the washer is draining properly but you are getting this code, you likely have a problem with the water level pressure switch or the control board.
If you need more help, resubmit your question with additional details and the full model number of your HE3 washer.