Hi Alvis,
You can find the complete troubleshooting instructions in one of my previous posts:
Freezer is fine, refrigerator is too warm.
- The part number for the defrost thermostat (#21 on the
system break down diagram) is
AP2150024
- The part number for the defrost heater (#14 on the
system break down diagram) is
AP2153549
- The part number for the defrost timer (#23A on the
shelves break down diagram) is
AP2111929
Here are the break down diagrams for the Frigidaire refrigerator
Model FRT21TNCW6
Gene.