Thermador Dishwasher Error Code E01 — Heating Timeout / Water Not Heating
What this means
Error E01 on Thermador dishwashers indicates the wash water temperature did not reach the programmed target within the allotted heating time. The control board monitors water temperature using the NTC sensor and expects a specific rate of temperature increase once the heater is energized. This code appears when heating is too slow or absent. Causes include a failed heating element, a faulty NTC temperature sensor giving incorrect readings, a tripped thermal fuse, extremely cold incoming water, or a wiring fault in the heater circuit.
Alternate codes: E:01, E1
Step-by-step fix
3 stepsRun hot water at the sink before starting the dishwasher
Run the hot water faucet closest to the dishwasher until the water is hot to the touch. This primes the hot water line so the dishwasher fills with hot water from the start rather than cold water that needs extensive heating.
If your hot water heater is far from the kitchen, the dishwasher may fill with lukewarm water. Running the tap for 1–2 minutes first can eliminate E01 in many cases.
Test the heating element
Disconnect power to the dishwasher. Access the heating element (beneath the tub on most Thermador models). Disconnect the element's wire leads and measure resistance with a multimeter. A good element reads 10–30 ohms. OL (open) means the element is burned out.
Thermador dishwashers with the Zeolite drying system still have a heater for wash cycles — do not confuse the Zeolite container with the heating element.
Check the NTC temperature sensor
The NTC sensor is near the heating element in the sump area. Disconnect it and test resistance at room temperature — expect approximately 50K–55K ohms. A sensor that reads too low will make the control think water is hotter than it is, causing it to stop heating prematurely.
If the sensor reads correctly at room temperature but E01 still occurs, the sensor may be drifting at higher temperatures. Replace it as a precaution.
When to call a professional
If the heater and sensor test good but water is still not heating, the relay on the control board that powers the heater circuit may be faulty — professional board diagnosis is needed.
Related error codes
Information compiled from manufacturer service manuals, official troubleshooting documentation, and appliance repair industry resources. This guide is for informational purposes only — always consult a qualified technician for complex repairs.
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