GE PFE28KELFDS bottom freezer, 4 years old. About a year or so ago I began to notice frost forming inside some frozen food packaging. Otherwise the freezer and reefer worked well and held temps. Run times for the compressor seem high but I understand this is normal for this model. Yesterday the freezer failed entirely, we found it at 40F. Reefer seemed to be working OK, holding a temp of 38-40F, but that may have just been delayed.

I unloaded the freezer, looked at the evap fan and evap coil, they looked OK, and there was no frost build up, the fan cycled periodically. I clean the condenser coils and fan religiously once a year, that deadline was about a month away, so I did it now, they weren’t especially dusty, but I cleaned them. As of last night, all seemed to be working, the freezer is back to 0
To +5F, I have it set at +5. Reefer at 38-40F, the set point. I see no frost on the evap coil, and the evap fan is running. I did a visual on the control board, nothing burned. As of just now the compressor and fans are off and the freezer and reefer have begun to warm again. I’m reluctant to reload the freezer. Is this indicative of a failing defrost T stat or defrost timer? I can use a multimeter.