I have a 6 year old GE Arctica side-by-side refrigerator that has intermittent problems maintaining the temperature. Some days the temperatures in the fridge and freezer are around 55°F and 28°F respectively, and other days it's 35°F and 5°F where they should be. I replaced the main control board which usually causes this problem but in this case it didn't solve the problem. The next most likely cause of this intermittent temperature control problem is thermistors (temperature sensors). So I ordered four of these thermistors (two in the freezer and two in the fridge) and they arrived quickly. I changed all four and the temperature problem was solved.