Our refrigerator/freezer will stop working (not... It starts off by making a strange noise. Like

Question

It starts off by making a strange noise. Like a long hum and a click. As if the compressor is attempting to come on but can't. It will do this for a couple of days then it will no longer cool or freeze. The fan is working, but blowing hot air. Then about 3 days after it has stopped it magically starts working again..and will for about 2 weeks. We have cleaned the coils as suggested in the manual, but it did not do anything to help it. Is it possible that the thermostat is going out? Our refrig is only 2 years old. We bought it brand new when we bought our house. What can we do to fix this problem?