Freezer runs continuously and forms heavy frost on the evaporator and interior walls.

Safety first: Unplug the freezer before accessing the evaporator and heater. Water from defrosting can create slip hazards; use towels.

Manual defrost:

• Turn off and unplug the freezer.
• Open the door and allow all ice to melt completely. Place towels to catch water and clear the defrost drain if accessible.

Inspect defrost components:

• Remove the rear interior panel to expose the evaporator, heater, and thermostat.
• Check for broken heater elements or loose thermostat clips.

Electrical tests:

• Test the defrost heater for continuity; an open circuit indicates failure.
• Test the defrost thermostat for continuity when cold; it should be closed.

Corrective actions:

• Replace failed heater or thermostat: Install Blomberg-compatible parts and ensure proper mounting.
• Clear drain: Flush the defrost drain with warm water to ensure it is not blocked by ice or debris.
• If heater and thermostat are good, the main control board may not be initiating defrost and may need replacement.

Test: After reassembly and restart, monitor over several days. Frost should remain light and confined to the evaporator, and the compressor should cycle off periodically.