Thermador Dishwasher Error Code E09 — Heating Element Fault
What this means
Error E09 on Thermador dishwashers indicates the heating element (either a flow-through heater or an in-tub heater depending on the model) is not raising the water temperature within the expected timeframe. The control board monitors the water temperature during the wash cycle and expects it to increase by a certain amount. If it does not, E09 is triggered. Causes include a burned-out heating element, a faulty temperature sensor (NTC), a blown thermal fuse, or a wiring issue to the heater circuit.
Alternate codes: E:09, E9
Step-by-step fix
3 stepsTest the heating element
Turn off the dishwasher and disconnect it from power. Access the heating element — on most Thermador models, it is a flow-through heater located beneath the tub, accessible by removing the bottom panel. Disconnect the wire leads and test with a multimeter for continuity. A working heater element reads 10–30 ohms. An OL (open) reading means the element is burned out.
Thermador's flow-through heaters are more efficient than in-tub heaters but are also more expensive to replace.
Check the NTC temperature sensor
The NTC (Negative Temperature Coefficient) sensor monitors water temperature. It is usually located near the heating element or in the sump area. Disconnect it and measure resistance — at room temperature, it should read approximately 50K–55K ohms (varies by model). A significantly different reading means the sensor is faulty.
NTC sensors decrease in resistance as temperature increases. If the reading is very low at room temperature, the sensor is shorted.
Check the thermal fuse
Some Thermador dishwashers have a thermal fuse in the heater circuit as a safety cutoff. Locate it near the heating element and test for continuity. A blown fuse (no continuity) must be replaced — and you should investigate why it blew (usually an overheating event).
A blown thermal fuse is often a symptom, not the root cause. Check for limescale buildup on the heating element, which can cause localized overheating.
When to call a professional
If the heating element, NTC sensor, and thermal fuse all test good but the water is still not heating, the control board or the relay controlling the heater circuit may be at fault. This requires professional diagnosis.
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.
Learn more about our sourcesParts you may need
Flow-Through Heating Element
Part #00649053 · $80–$180
If element reads open circuit on multimeter
Links may earn us a commission at no extra cost to you. We only recommend parts relevant to this repair.