Excessive frost or ice buildup on the evaporator and rear interior wall.

Safety first: Unplug the unit before defrosting or accessing internal components. Water may drip during defrost.

Steps to resolve heavy frost buildup:

• 1. Manual defrost: Turn off the cooler and leave the door open until all ice melts. Use towels to absorb water. Do not use sharp tools to remove ice.
• 2. Check door gasket: Inspect for tears, gaps, or hardened sections. Replace the gasket if it does not seal properly.
• 3. Inspect defrost components: Remove the interior rear panel to access the evaporator, defrost heater, and sensor. Test the heater and sensor as described for E4.
• 4. Drain check: Ensure the defrost drain channel is not blocked, allowing water to exit properly.
• 5. Control board: If heater and sensor are good but frost returns quickly, the defrost control on the main PCB may be faulty and require replacement.