Model Number:
Brand: Brand
Age: Less than 1 year

Model Number: TFX22ZPDA BB
Brand: GE
Age: More than 10 years

GE side by side started having a cooling issue, I found the evap coils to be frozen. My first step was to test the defrost timer so I tried to manually put it in defrost mode. The compressor and fan turn off but the defrosters do not heat up. The defrosters appeared to be in rough shape so I replaced both defrosters and the bimetal thermostat (kit that includes wiring harness) and I also replaced the defrost timer. I still manually try to put the refrigerator into defrost mode and the compressor and fan shut off but the defrosters still do not heat up. Is it possible I got a bad defrost timer? My understanding is the defrost system is pretty straight forward and I have replaced all the parts that make up the defrost system since it has a timer and not a control board. What else could be the problem? Is it possible the defrosters won't heat up if it has warmed up too much inside the freezer?