What E01 means on your Bosch dishwasher
Error code E01 indicates that the dishwasher’s heating system has failed to raise the water temperature to the programmed level within the expected time. The control board monitors the NTC (Negative Temperature Coefficient) sensor during the wash cycle. When the temperature doesn’t rise as expected, E01 is triggered and the cycle may pause or complete with cold water — leaving dishes poorly cleaned and potentially unsanitary.
Symptoms
- Dishes come out greasy, streaky, or with food residue
- The wash cycle runs longer than usual before displaying E01
- Water feels cold or lukewarm when the door is opened mid-cycle
- Detergent tablets don’t fully dissolve
Common causes
- Failed heating element — the flow-through heater develops cracks or loses continuity over time, especially in hard-water areas where mineral buildup insulates the element
- Faulty NTC temperature sensor — the sensor sends incorrect readings to the control board, either preventing the heater from activating or reporting false temperatures
- Control board relay failure — the relay that switches power to the heater can burn out, cutting power to the element even though the board sends the command
- Wiring harness damage — vibration or moisture can degrade connections between the heater, sensor, and control board
Troubleshooting steps you can try
- Power reset — turn off the dishwasher at the breaker for 60 seconds, then restore power. A temporary sensor glitch can cause a false E01 after a power outage.
- Check the hot water supply — run the kitchen faucet until the water is hot before starting a cycle. Bosch dishwashers perform best with an incoming water temperature of at least 120°F (49°C).
- Inspect the water inlet — ensure the hot water valve under the sink is fully open. A partially closed valve reduces flow and makes it harder for the heater to reach temperature.
- Run a test cycle — select the hottest program (Sanitize or Heavy Wash) and let it run. If E01 appears again, the issue is internal.
When to call a technician
If the code returns after a reset and confirming hot water supply, the heating element or NTC sensor likely needs replacement. Both components are located inside the sump assembly at the base of the dishwasher and require disassembly to access. A technician will test continuity on the heater (should read 10–30 ohms) and resistance on the NTC sensor (should read approximately 50k ohms at room temperature). Operating the dishwasher with a persistent E01 won’t cause further damage, but wash quality will be poor and high-temperature sanitization won’t function. Codes may vary by model generation and series.
Need help? Schedule Bosch Dishwasher repair with a certified technician, or contact our team for a free diagnosis consultation.
