We have a Frigidaire 16 cubic foot frost-free upright freezer. Most of the time it will maintain a -10°F. temperature. Periodically, perhaps every 6 months or so, the temperature rises to between 10-20° above 0°F. If I remove the contents and allow the freezer to stand empty with the door open for 24 hours, when I power it up again, it will return to the -10°F. temperature and maintain that again for at least 6 months.
Any ideas on what may be cause this?
TIA