Ice maker will not run; display shows E1 and unit may beep periodically.

Safety first: Unplug the Marvel ice maker or switch off the circuit breaker before removing any panels.

Steps to check the evaporator thermistor:

• Remove the toe‑kick or lower front grille to access the front service area (on many Marvel undercounter units the thermistor harness routes from the evaporator compartment to the control board at the front or rear).
• Locate the evaporator thermistor: it is usually a small, bullet‑style sensor clipped to the evaporator plate or tubing with two wires leading back to the control board.
• Disconnect the thermistor connector from the harness.
• Using a multimeter set to resistance (ohms), measure the thermistor at room temperature. Compare the reading to the Marvel service chart (typical NTC thermistors are around 5k–10kΩ at 77°F/25°C). An open (OL) or 0Ω reading indicates a bad sensor.
• Inspect the wiring harness for pinched, cut, or corroded wires and loose connectors at the control board.
• If the thermistor is out of spec or physically damaged, replace it with a Marvel‑approved evaporator thermistor. Clip it back in the same location and route the wires away from sharp edges and moving parts.
• Reconnect the harness, restore power, and clear the error by powering the unit off for 5 minutes, then back on. Verify that the E1 code does not return and that the unit begins a harvest cycle.

If E1 persists after replacing the thermistor and verifying wiring, the main control board may be faulty and should be tested or replaced by a qualified technician.