Whirlpool refrigerator defrost problems are when your refrigerator does not melt away the frost that builds up in the freezer when it is running. This causes a lack of airflow, which results in a cooling problem.
On most refrigerators, all cooling is done in the freezer section. You will notice the fresh food and the freezer becoming warmer than normal.
How to Identify a Defrost Problem
Beyond the effect on cooling, you will begin to notice a light frost building up on the back wall of the freezer. The frost will increase as the refrigerator continues to warm.
What is Happening?
The evaporator is a set of coils in the freezer section that maintains the cooling for the refrigerator. The cold air cannot flow away from the evaporator if too much frost is built up.
The refrigerator's age might be an indication of why it isn't defrosting. Whirlpool refrigerators made before 2001 will have a defrost timer that can be bad. Refrigerators made after 2001 will have an electronic defrost control instead.
Top Mount or Side-by-Side
Top-mount freezers and side-by-sides also have different problems. Top-mounts are more likely to have a bad defrost thermostat, while side-by-sides are more likely to have a bad defrost heater.