Display shows E12; unit may not defrost properly or may have heavy frost buildup.

Safety: Disconnect power before accessing any heater or wiring. Heaters can be hot and line‑voltage energized.

Steps:

• Remove interior panels to access the evaporator area and any defrost or anti‑frost heaters (some Marvel ice makers use small heaters to prevent plate icing or door gasket frost).
• Inspect for broken heater elements or burned wiring.
• Use a multimeter to test the heater for continuity. An open circuit indicates a failed heater that must be replaced.
• Locate the defrost thermostat or thermal fuse (if present) and test for continuity when cold. Replace if open when it should be closed.
• Check wiring from the heater and thermostat back to the control board for damage.
• If heater and thermostat test good, the control board’s defrost relay may be faulty and the board may need replacement.
• After replacing any failed components, manually defrost heavy ice buildup by allowing the unit to sit unplugged with the door open and towels in place to catch water. Do not chip ice with sharp tools.