Were is the defrost timer

Check your defrost timer also make sure its turning also there's a thermostat and heating element that defrost the ice at given cycles

usually when aq defrost timer goes bad it gets stuck in defrost. I would suggest replacing this first

either defrost timer or cold control

Good day,
Sounds as if the defrost system has failed. You didn't give the make and model number but here is an excellent tutorial on automatic defrost systems.

http://www.appliance411.com/faq/howdefrostworks.shtml

It sounds to me like the defrost isn't working somewhere.It freezes for 2 weeks until the evaporator coil freezes over and you lose your airflow, hence, your cooling. Then when you shut the unit off for 6 hours it thaws out enough to get you cooling again for 2 weeks.Check your defrost timer and see if it is going into defrost and if your defrost elements are good. Both will be located on top of the unit. Good luck!

You have a defrost problem. Either the defrost timer is not working to put it into an auto defrost, or you have a bad defrost heater or DTS (defrost thermostat switch).

Check rear wall of freezer by feel for frost. Heavy, even frost indicates likely problem in the defrost system. Unplug unit. Defrost heater (in freezer behind rear wall panel), defrost thermostat (same area-must be checked at freezer temperature) or Defrost timer-located lower back outside of unit. Near compressor. Do continuity test on heater and defrost thermostat and if they show continuity (good), replace defrost timer. If not, replace the one that tests bad.

Defrost coils fully. Reassemble.

Please let me know if I have helped with comments and rating.

Refrigerator will work about 7-10 days after being defrosted until thick frost builds up again cutting off air flow to both compartments

Sounds like a defrost timer.Also it can be a defrost thermostat.Try to adcance the defrost timer to a defrost and see if it melts the ice off.If so then i would say you need a defrost timer hope i helped:)

Check the defrost timer for operation if your unit has one. Some Delfield models have solid state controls. If your system has a timer for the defrost you can open the timer cover and turn the dial in the direction indicated by the arrow until a time peg comes up to the time of day marker. You will hear a loud click and the compressor will shut off. Defrost should take place. The inner dial of the timer will have some indication as to how long in minutes the defrost should take. If the pointer does not move while in the defrost position the timer motor is bad. Turn the dial again so the copper pointer goes past the time of day marker and the compressor should restart. Replace the timer.

No model # .. Im assumeing its frost free.. so that means a defost problem.. heaters, defrost themostate or timmer.