This is a Eterna series made for HHGregg.Not sure how old.The model is ERS2022DA CC. The heater was replaced about 3-4 yrs. Ago. I just thawed out the freezer 2 weeks ago and it is froze up again. Not sure what to replace to fix the freezing up and refridge side getting warm.Please I need help fast .

Thanks
Indy375

Frost-free freezers have "defrost timers" in them. The defrost timer periodically turns on heat at the walls of the freezer. This causes ice clinging to the surface to melt and run off. If your freezer is freezing up, it's likely that the defrost timer has failed.

How can you determine if it is the defrost timer or defrost thermostst?

The Defrost Thermostat is usually a bimetallic strip. The defrost timer uses an electrical motor. The defrost thermostat can be checked for continuity (it should be normally closed) using an ohmmeter. The defrost timer can be rotated manually. If you rotate it and the contacts close (thus providing power to the heating circuit), then you know the contacts are working. Make sure the motor is actually turning. If this doesn't check out, replace the defrost timer. Also, make sure the circuit is continuous through the heating elements (ohmmeter). Heaters won't heat unless the circuit is complete.