Freezer forms excessive frost or ice on the evaporator and inner walls; airflow is restricted and temperature rises.

Safety: Unplug the freezer before defrosting or accessing internal components.

• Manual defrost: Open the door and allow all ice to melt completely. Place towels to catch water. Do not use sharp tools or high heat sources.
• Access evaporator: Remove the inner rear panel to inspect the evaporator and defrost components.
• Test defrost heater: Disconnect heater leads and measure resistance. Replace if open.
• Check defrost thermostat / fuse: Test for continuity at freezer temperature. Replace if open and secure it to the evaporator tubing.
• Control check: On mechanical-timer models, rotate the defrost timer to see if the heater energizes. On electronic models, the PCB controls defrost; if all components are good, the PCB may be faulty.

Test: After replacing faulty parts and reassembling, monitor frost buildup over 1–2 weeks. The evaporator should remain mostly clear with only a light, even frost.