Hi

Thanks for using FixYa. In a self-defrosting freezer, poor cooling often results from a heavy frost build-up on the evaporator coils. To access these coils you need to remove panel inside the freezer. If there is any frost or ice build-up on the inside walls, ceiling, or floor it’s sign of frost build-up and it means a problem with the self-defrosting system. Freezers should self-defrost three to four times in 24 hours. In case a component in the self-defrosting system fails, the freezer continues to try to cool, instead. Eventually, so much frost builds up on the evaporator coils that the circulating fan can't draw air over the coils. There is some cooling as the coils are frozen. But with no air flow over the coils, the cooling is quite limited and the freezer isn't cold as normally it should be. To check the de frosting system problem, you need to remove all of the perishable food from the freezer, turn the thermostat to off, leave the door open for 24 to 48 hours to "manually" defrost the freezer. After the frost and ice build-up is completely melted away, turn the thermostat back to a normal setting. If it is cooling properly, it indicates a problem with one of these components in the self-defrosting system:

• The defrost timer – To test this, manually advance the defrost cycle. The unit should advance itself out of the defrost cycle in about 45 minutes.
• The defrost thermostat – This allows current to pass through it at temperatures of 20 to 30 degrees Fahrenheit and prevents current from passing through it at 40 to 60 degrees. This is difficult to test, though, because it takes a prolonged, very-cold temperature to turn it on.
• The defrost heater – You can test this for continuity using an electrical meter.