E11
Bosch Dishwasher
Severity: ModerateWhat Does This Error Mean?
The E11 error means the water temperature sensor (NTC thermostat) inside your Bosch dishwasher has failed. The control board cannot read the water temperature during the wash cycle. Without this reading, the machine cannot control heating correctly.
Affected Models
- Bosch 300 Series
- Bosch 500 Series
- Bosch 800 Series
- Most Bosch built-in dishwashers
Common Causes
- NTC temperature sensor has failed — open or short circuit
- Wiring connector to the NTC sensor is loose or corroded
- Limescale buildup has coated the sensor and is causing inaccurate readings
- Sensor was damaged by overheating in a previous cycle
- Main control board has a fault affecting sensor signal interpretation
How to Fix It
-
Power cycle the dishwasher — unplug for 5 minutes and restore power.
A reset can clear a temporary NTC sensor communication error.
-
Run a descaling cycle or use a dishwasher cleaning tablet.
Heavy limescale buildup on the sensor can cause false temperature readings. A cleaning cycle may help.
-
Check if your area has very hard water — install a water softener if limescale is a recurring issue.
Bosch dishwashers have a built-in water softener — make sure it is filled with the correct dishwasher salt.
-
Refill the dishwasher's salt reservoir if the salt indicator light is on.
Running the dishwasher without salt in hard water areas accelerates limescale buildup on sensors and heating elements.
-
If E11 persists after cleaning and reset, the NTC sensor needs professional replacement.
Do not ignore this — without a functioning temperature sensor, the dishwasher cannot clean or sanitize properly.
When to Call a Professional
An NTC sensor is an inexpensive part but requires partial disassembly to access. A technician can diagnose and replace it in under an hour. Expect repair costs of $90–$180 for sensor replacement and labor.
Frequently Asked Questions
What is an NTC sensor in a dishwasher?
NTC stands for Negative Temperature Coefficient. It is a small electronic sensor that measures water temperature inside the dishwasher. As the water gets hotter, the sensor's electrical resistance decreases — the control board reads this change and knows the water temperature.
Can limescale really trigger an E11 error?
Yes — heavy limescale insulates the sensor from the water, causing it to read temperatures inaccurately. In hard water areas, this is a surprisingly common cause of temperature errors. Regular use of dishwasher salt and cleaning tablets prevents this.
How long does an NTC sensor last in a Bosch dishwasher?
NTC sensors typically last 8–12 years under normal use. Hard water areas and infrequent descaling can shorten the lifespan significantly. Replacing one is affordable and usually extends the dishwasher's useful life considerably.