Ice maker indicates a defrost or de-icing error; evaporator plate remains iced over.

Safety first: Disconnect power before accessing the evaporator or heater. Avoid using sharp tools to remove ice.

Steps:

• Manual defrost: Remove ice from the bin and open internal panels to expose the evaporator plate. Allow the unit to sit unplugged with the door open until all ice melts, or use a hair dryer on low setting at a safe distance to speed up melting.
• Inspect heater: Locate the defrost heater (if fitted) around or beneath the evaporator. Test for continuity with a multimeter. Replace the heater if open.
• Check defrost thermostat: The thermostat or thermal fuse is usually clipped to the evaporator. Test for continuity when cold; replace if open.
• Examine for scale: Mineral scale can insulate the plate and interfere with defrost. Run a manufacturer-approved descaling cycle using SMEG ice maker cleaner according to the manual.
• Control board: If heater and thermostat are good but never receive power during defrost, the PCB defrost relay or control logic may be faulty and the board may need replacement.