Thermador Dishwasher Error Code E17 — Overfill / Water Level Too High
What this means
Error E17 on Thermador dishwashers indicates the water level in the tub has exceeded the maximum safe level. The water level sensor or float switch detects that water is higher than expected. This can be caused by a faulty water inlet valve that is not closing (letting water in continuously), a clogged drain, a malfunctioning water level sensor, or backflow from the sink drain through the drain hose. The dishwasher will activate the drain pump and stop the cycle.
Alternate codes: E:17
Step-by-step fix
3 stepsCheck for a stuck water inlet valve
Turn off the water supply valve immediately. If water continues to enter the tub after the dishwasher is powered off, the inlet valve is stuck open. Turn off the water supply and disconnect power. The valve must be replaced.
A stuck-open inlet valve is a flood risk. Always turn off the water supply before investigating to prevent overflow.
Inspect the drain hose for backflow
Check that the drain hose has a high loop (at least 20 inches above the floor) or is connected to an air gap device. Without a high loop, dirty water from the sink can siphon back into the dishwasher, raising the water level. Also check that the sink drain is not clogged.
If your Thermador dishwasher is installed in an island without an air gap, a high loop is absolutely critical to prevent backflow.
Test the water level sensor
The water level sensor (turbidity or analog pressure sensor) is typically located in the sump area. If the sensor is giving a false reading, it may trigger E17 even when the water level is normal. Consult the service manual for your specific model to locate and test the sensor.
Cleaning the sump area thoroughly can sometimes resolve sensor issues caused by debris interfering with the pressure sensor tube.
When to call a professional
If the water inlet valve is stuck open, replace it urgently — this is a flood risk. If the sensor is faulty, professional diagnosis is recommended to avoid misidentifying the problem.
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
Water Level Sensor / Pressure Switch
Part #00497570 · $30–$55
If sensor is giving false readings
Links may earn us a commission at no extra cost to you. We only recommend parts relevant to this repair.