Amana freezer shows E4 and may not defrost properly, leading to frost buildup on the evaporator cover.

Safety: Unplug the freezer. The defrost heater and wiring can be live and hot during operation.

Steps:

• Access evaporator and defrost components: Remove baskets and the rear interior panel to expose the evaporator coil.
• Locate defrost thermostat and heater: The defrost thermostat (bi-metal) is clipped to the evaporator tubing; the heater is mounted at the bottom or woven through the evaporator.
• Check for heavy frost: If the coil is a solid block of ice, manually defrost with a hair dryer on low, keeping it away from plastic and wiring. Do not chip ice with sharp tools.
• Test the defrost thermostat: With the coil still cold, disconnect the thermostat and check continuity. It should be closed (continuity) when cold. If open when cold, replace it.
• Test the defrost heater: Disconnect the heater leads and measure resistance. A typical heater will show some resistance (e.g., 20–100 Ω). If it reads open, replace the heater.
• Inspect wiring: Check the harness from the heater and thermostat back to the control board for burns or breaks. Repair as needed.
• Control board: If heater and thermostat test good, the control board may not be energizing the defrost circuit. Replace the board if the defrost relay is faulty.

After repair: Reassemble panels, plug in the freezer, and allow 24 hours for temperatures to stabilize.