Why does my water line in the freezer door keep freezing and how do I set the defrost timer and where is it
As for a defrost timer, this unit does not have one. The defrost is controlled by the main control board and thermistor. As for the water line in the door, this would freeze due to temps getting too cold in the freezer compartment and there being a void in the insulation of the door. If the start of your serial number is AF through AM then there is a service kit part number WR49X10173 to correct this issue.
My bottom-freezer refrigerator has an L55-30F thermostat. Can I replace it with an L140-30F thermostat that I happen to have?
Answer Chris, No, don't use the L140 -30 F thermostat. Use the proper part WR50X133. The range is triple the temperature range, you'll create other issues with the defrost cycle and cooling of the refrigerator if you do.