Hi Bill,
The defrost timer is located in the fresh food compartment (#257 on the
break down diagram).
The defrost heater and the defrost thermostat are located behind the rear panel in the freezer (d/heater - #230 on the
break down diagram) and d/thermostat - #240 on the
break down diagram).
You can find the complete troubleshooting instructions in one of previous posts:
Freezer is fine, refrigerator is too warm.
- The part number for the defrost timer is
AP2061695
- The part number for the defrost heater assembly (including the defrost thermostat) is
AP2071523
- The part number for the defrost thermostat is
AP2071262
Here are the break down diagrams for the GE refrigerator
Model TFX22PRDAWW
Gene.