there are tow things that can cause this, 1 the fill valve is bad, or 2 the float, check the float and make sure it moves up and down freely and you hear a slight click, if you do replace the valve, you can order this @ http://www.repairclinic.com/SSPartDetail.aspx?s=t-GSD6600G00WW-%3d%3dei785330&PartID=785330 thanks Bryan
How do you test the float value?
Also, what is the reference number for this case?
Is the float part # XXXXX? If the float is not working correctly the valve will not operate. Is this correct?
What is the part number for the float/micro switch?