Freezer shows error and defrost does not occur, heavy ice on evaporator, fan noise changes over time

Safety first: Unplug the freezer before accessing the evaporator or heater. Do not use sharp tools to remove ice from coils.

Steps:

• Inspect evaporator: Remove interior rear panel to expose the evaporator. If it is completely encased in ice, the defrost system is likely not working.
• Locate heater and thermostat: The defrost heater is usually a metal or glass-encased element at the bottom or woven through the evaporator. The defrost thermostat (bi-metal) is clipped to the coil.
• Test heater: Disconnect heater leads and measure resistance with a multimeter. A typical reading is between 20–200 Ω. Infinite resistance indicates an open heater.
• Test defrost thermostat: If the coil is cold and frosted, the thermostat should show continuity. If it is open when cold, it is defective.
• Check wiring: Inspect connectors and wires for burns or breaks between heater, thermostat, and control board.
• Replace faulty parts: Install a new OEM Hotpoint defrost heater and/or defrost thermostat as needed. Ensure the thermostat is clipped firmly to the coil.
• Manual defrost: Fully defrost the evaporator with the unit unplugged before reassembly to start with a clear coil.
• Restore power: Refit panels, plug in the freezer, and monitor over several days to confirm frost does not build up again.