An E6 error code of the Bosch dishwasher means that there are problems with the sensor that controls the water turbidity. It is also called the Aqua Sensor.
In the dishwasher, this sensor detects the turbidity of the water due to the presence of small particles of dirt, food residues and other things inside it. It allows you to change the course of the program: its duration and water consumption, which helps to save electricity.
How does the Aqua Sensor work and why do I need a water quality sensor?
The dishwasher’s Aqua Sensor is an infrared photodiode and a phototransistor, installed on a general board opposite each other. The board is protected by a light-proof casing that has a curved shape in the form of a letter “U”. The infrared beam sent from the photodiode passes through the water and enters the phototransistor. When the water is clean, the control board receives a signal, and the washing program changes: clean water is reused, new water is not poured, and additional rinsing of dishes is canceled.
If the water is contaminated, then the intensity of the beam is not enough for the phototransistor to work. In this case, the microprocessor of the Aqua sensor system sends information to the control module about the absence of a signal from the phototransistor, which is perceived as turbidity of water. After each rinse cycle, the sensor is calibrated and the purity level of the water is determined. This method of automatic dishwashing can save up to 4 liters of water per wash, while the quality of washing remains excellent.
Important! The sensitivity of the photocell sensor of the turbidity sensor depends also on the formation of scale and the residue of detergents in the water.
The water purity sensor is located at the bottom of the dishwasher. It can be seen by removing the left cover of the dishwasher case. The water sensor is inserted into the connector of the circulation pump, and therefore its replacement in the case of a breakdown will not be very difficult. Sometimes the aqua sensor can be repaired by changing the burned contacts, but in most cases, it is better to replace it.