My refridgerator/freezer builds up frost in the freezer.Throughout the day i hear the appliance 1 0r 2 times automatically turn off then back on again,but during that time the frost does not melt.Near the bulb i took out timer i believe its called and i turned it maually til it clicked and it turn off then about 20 min or so it automatically turned back on.Coils felt like they were cold ,like nothing was heating.So do you believe it could be the thermostat..
Most likely the defrost heater is no good. The timer thing is a defrost timer, 20 min. sounds about right, should turn on a foil strip heater up in evaporator section of freezer. Thermostat won't have anything to do with defrost.