Kenmore electric water heater with electronic display shows E01 and will not heat water

Safety first: Turn OFF power at the breaker (240V can be lethal). Verify with a non-contact voltage tester at the heater junction box before touching any wiring.

• Power reset: Turn the water heater breaker OFF for 5 minutes, then back ON. If E01 returns immediately, continue below.
• Access the upper panel: Remove the upper access cover, insulation, and plastic shield to expose the upper thermostat/element area and sensor harness.
• Inspect wiring: Look for loose, burned, or broken wires going to the upper thermistor (usually clipped to the tank or inserted into a well). Reseat connectors firmly.
• Test thermistor: Disconnect the thermistor from the harness. Using a multimeter set to resistance (ohms), measure across the sensor leads. Compare reading to the service chart for your Kenmore model (typically 10–50 kΩ depending on water temperature). An infinite reading indicates open; near 0 Ω indicates shorted.
• Replace if defective: If the thermistor is out of spec, replace it with the correct Kenmore upper tank temperature sensor/thermistor. Clip or insert it in the same location and reconnect the harness.
• Check control board: If the thermistor tests good but E01 persists, inspect the main control board for burnt spots or corrosion. In many cases the board must be replaced.
• Restore power and test: Reinstall insulation and cover, restore power, and verify that the code clears and the heater begins to warm water.