Magic Chef Refrigerator CSB2121ARA Freezer not defrosting

This refrigerator defrost heater and thermostat assembly restores proper automatic defrosting. The heater melts ice buildup on the evaporator, while the thermostat shuts off power at the right temperature to protect components and keep cooling consistent.

• Heats the evaporator during the defrost cycle to clear frost and ice
• Thermostat opens the circuit as the coil warms, preventing overheating
• Helps restore airflow across the coil and stable fridge/freezer temperatures
• Common symptoms: heavy frost behind the freezer panel, poor cooling or warm temps, fan noise from ice contact, unit not defrosting

• Disconnect power before servicing; remove freezer shelves/bins and the rear panel to access the evaporator
• Carefully defrost built-up ice; note original wire routing and clip locations
• Transfer any brackets/clips and mount the new assembly in the same positions
• Ensure connectors are fully seated and wires are clear of the fan and moving parts before restoring power