How to Fix / Troubleshooting

Safety: Unplug the freezer before accessing the evaporator and electrical components.

Steps:

Manual defrost first: Remove the interior rear panel and allow all ice to melt naturally or with warm water. Do not use sharp tools.
Test defrost heater: Disconnect heater leads and measure resistance. Replace the heater if open.
Check defrost sensor/fuse: Test continuity of the defrost thermostat or thermal fuse (if present) at freezing temperatures. Replace if open when it should be closed.
Inspect defrost thermistor: Measure resistance and compare to specifications. Replace if out of range.
Control board: If all components test good, the control board may not be initiating defrost cycles and may need replacement.

Note: After repair, monitor for several days to ensure frost does not rapidly return.

Thick ice buildup on the evaporator coil behind the interior panel; airflow is restricted

Possible Causes