Common Bosch Dishwasher Error Codes

Dejan Josipovic
10 Minute Read

You'll be happy to learn that Bosch dishwashers feature error codes to assist homeowners and appliance repair professionals, like the crew at The Appliance Guys, in identifying and troubleshooting dishwasher problems. These error codes can represent a number of difficulties, ranging from problems with the water supply to flaws in the electrical control board of the dishwasher. A dishwasher may notify the user to the precise issue at hand by showing an error number, which makes identifying and resolving the issue simpler.

While you can maintain and troubleshoot your dishwasher on your own for certain straightforward faults, it might be risky to try to solve more complicated problems by yourself. If you need to start taking the dishwasher apart, we advise that you hire a qualified dishwasher repair specialist. Dishwashers involve electricity and water, so you run the risk of hurting yourself or others if you are unfamiliar with the device or don't have the right tools and safety equipment. Additionally, if you make a mistake while attempting to fix your dishwasher, you can end up doing more harm and end up needing to do more extensive repairs. As a result, it is always better to leave appliance repairs to the experts.

Error Code: Fault Description:
Bosch Error Code E01

Power Module Fault (Pump Circuit Failure or Heating Issue)

The E01 error code refers to a pump control circuit failure on the main control board, however, with some dishwasher models, the fault can cause a lack of water in the dishwasher, which stops the heater from running and triggers the error code.

Bosch Error Code E02

Power Module Fault (Heater Relay or Heating Issue)

The E02 error code indicates that the heater relay on the control board has a fault. With some models, the error can be caused by a faulty temperature sensor or thermistor.

Bosch Error Code E03

Power Module Fault (Aux Heater Relay Fault or Water Inlet Valve Failure)

An E03 error code refers to an auxiliary heater relay fault on the main control board. However, with some models, it indicates that the water inlet valve needs to be replaced because the dishwasher cannot fill with water.

Bosch Error Code E04

Power Module Fault (Heating Fault or Water Issue)

The E04 error code refers to a heating issue, which can be very difficult to diagnose. With some models, it may indicate that a spray arm is clogged and needs cleaning, or that the water flow sensor needs to be replaced.

Bosch Error Code E05

Power Module Fault (Water Switch Triac Fault or Float Issue)

The cause of the E05 error code is a water switch Triac fault on the main control board. In some cases, the error code indicates a damaged float or defective float switch.

Bosch Error Code E06

Door Mechanism Failure or Aqua Sensor Fault

Depending on the dishwasher model, the door may not be closing properly, or the aqua sensor may have a fault. Most likely it's a door mechanism failure, unfortunately, the sensor is difficult to access, and a door mechanism failure can be difficult to diagnose.

The aqua sensor (turbidity sensor) monitors the water quality, such as whether the water is clean or dirty. The aqua sensor is located on the circulation pump.

If the door is closing and locking, the sensor switch that monitors the door may be faulty and need to be replaced, or the main control board may have a fault.

Bosch Error Code E07

Drying Fault

Either the drying fan or wiring from the control board to the drying fan needs to be checked and potentially replaced.

Bosch Error Code E08

Loss of Water

The water level unexpectedly dropped during the cycle. Check for overturned dishes collecting water or a water supply issue.

Bosch Error Code E09

Heating Fault

The main control board may have a heater relay fault, or the heater may be defective. The heater’s resistance can be checked with a multimeter to determine if it has failed. A trained technician will need to check the control board.

Bosch Error Code E10

Slow Heating

The water heater may be affected by excessive limescale, or it may be defective. Deep cleaning and descaling the dishwasher may resolve the issue, or the heater may need to be replaced.

Bosch Error Code E11

Thermistor or Temperature Sensor Fault

The resistance of the thermistor (integrated into the heat pump on newer models) or the NTC (temperature sensor) needs to be checked to diagnose the issue (see the tech sheet for the required resistance).

Bosch Error Code E12

Slow Heating

The water heater may be affected by excessive limescale, or it may be defective. Deep cleaning and descaling the dishwasher may resolve the issue, or the heater may need to be replaced.

Bosch Error Code E13

Water Temperature is Too Hot

Check the dishwasher is getting cold water and that the temperature sensor does not have a fault (check the sensor’s resistance with a multimeter).

Bosch Error Code E14

Water Inlet Fault

The dishwasher’s flow meter (also called a reed switch) is not detecting that water is entering the dishwasher. The most common cause is a faulty flow meter. The flow meter is located on the heat exchanger and can be relatively easily removed and replaced to resolve the error code.

Bosch Error Code E15

Dishwasher is Leaking

First, determine if you can see where the leak is coming from. If the dishwasher does not appear to be leaking, the flood sensor in the drain pan underneath the tub may be defective. Otherwise, a hose may be loose, or a gasket or spray arm may be damaged.

Bosch Error Code E16

Water Inlet Fault

The dishwasher is filling with water when it shouldn’t. Replace the water inlet valve to fix the issue.

Bosch Error Code E17

Water Level to High check flow sensor

The E17 error indicates that there is most likely an issue with the dishwasher water level being too high. When water enters the sump, it passes via a float chamber; if the level in the machine causes the float to rise, it indicates surplus water and activates the flood function, causing the pump to start working.

This can occur if the piping from the float chamber is blocked from grease build up. If the dishwasher is overflowing with water or displays this error message, Examine the tubing for obstacles that could cause the dishwasher to overfill with water. Remove any gunk and test the wash.

If the problem persists, make sure the float and switch are working properly and replace the float switch if necessary. We were unable to locate any additional information about your specific model. I have attached a service manual and also a video on float switch replacement.

Bosch Error Code E18

Water Level too Low check valve

The E18 error code means the dishwasher is not filling with water. Check that the water supply line is turned on and not kinked. If the issue remains, replace the water inlet valve.

Bosch Error Code E19

Dispenser or an Internal Valve

If the E19 error code appear it means that there is a problem with the dispenser or an internal valve (recirculating valve).

Bosch Error Code E20 Winding resistance of circulating pump fault
Bosch Error Code E21 Circulating pump blockage
Bosch Error Code E22

Blocked filter

The dishwasher’s filter needs to be emptied and cleaned of debris.

Bosch Error Code E23 Winding resitance of drain pump fault
Bosch Error Code E24 Drain filters blocked
Bosch Error Code E25

Drain Pump Blocked, Pump Cover Missing

The E25 error code indicates the drain pump is blocked or the drain pump cover is loose or missing.

Bosch Error Code E26

Diverter Motor Fault

The E26 error code is a diverter motor fault when the main PCB has not detected any change in the position of the motor. Error E26 could be cause by a faulty diverter valve motor or a broken piece of glass stuck in the diverter valve preventing the valve from rotating.

Bosch Error Code E27

Under Voltage Error

The power module is receiving bellow operation voltage from the power point. Check voltage from the power point, if house power supply is good, replace the power module.

Bosch Error Code E28

Aqua Sensor Fault

(see Error code E06)

Bosch Error Code E29

Low Mains Voltage

The dishwasher is receiving below the required voltage to operate. Measure the voltage at the power point. If no power supply issues found, replace the power module.

Bosch Error Code E30

Voltage Too High

The power module is receiving voltage over 290V and is too high. Very rare error code to be seen on Bosch dishwashers.

Please note that Bosch dishwasher error codes serve as a troubleshooting reference and are not always accurate. We have worked on several Bosch dishwashers in the past where the malfunction was with a totally different component than what the error number indicated; thus, you will require a professional appliance specialist to identify the problem.

Leave a comment

Please note, comments need to be approved before they are published.