Freezer interior is warm but compressor and fans are running; heavy frost or solid ice on back wall or evaporator cover.

Safety first: Unplug the freezer. Water from melting ice can create slip and shock hazards; use towels and keep the area dry.

Steps:

• Manual defrost: Remove food and shelves. Take off the rear interior panel and allow all ice to melt naturally. Do not use sharp tools to chip ice.
• Test defrost heater: With the heater exposed, disconnect one lead and check continuity with a multimeter. Replace the defrost heater if open.
• Check defrost thermostat: While the evaporator is still cold, test the defrost thermostat for continuity. Replace if open when cold.
• Inspect wiring: Look for burned or broken wires in the defrost circuit.
• Control board: If heater and thermostat are good, the main control board may not be sending power to the heater and should be replaced.

Tip: After repair, monitor for several weeks to ensure frost does not build up again.