Frost build-up in a frost-free refrigerator is the most common problem of all. Excess frost can be caused by an excessive amount of humid air, like a door left open, or lack of heat in the defrost cycle. Poor air circulation can even cause frost up. A high flow of air helps to dry out the evaporator.

Following is a list of the reasons for frost build-up:

1. Bad defrost clock
2. Open defrost limit
3. Open defrost heater
4. Door left open
5. Bad door gaskets
6. Bad evaporator fan motor
7. Restricted air flow

Frost Present
Marginal Temperatures
Some Cooling
Troubleshooting Refrigerators
Diagnostic System