Machine displays E04 and stops; often occurs during freeze cycle or shortly after start.

Safety first: Disconnect power before accessing internal components. Avoid bending or damaging the evaporator grid.

Steps:

• Access evaporator area: Remove the front panel. Locate the evaporator plate/grid and find the thermistor (small sensor clipped to the plate or tubing).
• Check sensor mounting: Ensure the thermistor is firmly clipped to the evaporator surface and has good contact. Re‑clip if loose.
• Inspect wiring: Follow the thermistor wires back to the control board. Look for cuts, abrasions, or loose connectors. Reseat the connector at the board.
• Test/replace thermistor: Using a multimeter and the Manitowoc service chart, measure resistance at room temperature. If the reading is far off spec, replace the evaporator temperature sensor (thermistor).
• Reset and test: Restore power, clear the error (if applicable), and run a test cycle to confirm normal operation.

Note: If a new sensor does not resolve E04, the control board’s sensor circuit may be defective and require replacement.