Ice maker stops mid-cycle and displays E04; ice plate may be heavily frosted or iced over.

Safety first: Unplug the unit. Allow any heavy ice buildup to melt before working near the evaporator to avoid damage.

• Inspect for heavy frost: Remove the ice bin and front cover. If the evaporator plate is encased in ice, allow it to defrost completely (use towels to catch water; do not use sharp tools).
• Locate the harvest/defrost thermistor: On many Weasy models, a small bead-type sensor is attached to the evaporator or ice grid with a clip or bracket.
• Check attachment: Ensure the thermistor is firmly in contact with the metal surface. Re-secure with the original clip or a metal clamp and thermal paste if it has come loose.
• Test the thermistor: Disconnect from the harness and measure resistance at room temperature. Compare to the Weasy thermistor chart. Replace if open, shorted, or far out of spec.
• Inspect wiring: Follow the thermistor wires back to the control board. Look for pinched, cut, or chafed insulation, especially where wires pass through panels.
• Clear the error: After replacing the thermistor and defrosting, restore power and run a test cycle. If E04 returns with a known-good sensor, the main control board may need replacement.