Bosch Dishwasher Error Codes: Troubleshoot Issues Easily

Bosch dishwashers are known for their innovative features and reliable performance. However, like all appliances, they may occasionally display error codes when operational issues occur.

Understanding these codes can help you quickly identify and resolve problems, ensuring your dishwasher continues to run smoothly.

In some cases, replacing specific Bosch Dishwasher Parts may be necessary to restore full functionality. Below is a helpful guide to common Bosch dishwasher error codes, their potential causes, and recommended troubleshooting steps.

E01 – Heat Pump Motor Circuit Fault

Issue:

The dishwasher has detected a malfunction in the heat pump motor circuit, which is responsible for circulating and heating water during the wash cycle. When this fault occurs, the dishwasher may stop mid-cycle or fail to start entirely.

Possible Causes:

A faulty heat pump motor that no longer circulates water effectively
Burned, frayed, or disconnected wiring between the heat pump and control board
A defective main control board that fails to deliver the correct power to the motor

Solutions:

Start by resetting the dishwasher. Turn off the power at the circuit breaker for at least 30 seconds, then restore power and try running a cycle again.
If the error code reappears:

Inspect the wiring and connections to the heat pump motor for signs of damage or corrosion.
If the motor appears damaged or isn’t operating, it may need to be replaced.
If the motor and wiring are intact but the error persists, the main control board may be faulty and require professional diagnosis or replacement.

For most cases involving motor circuit faults, it’s recommended to contact a Bosch-authorized technician to ensure accurate diagnosis and safe repairs.

E02 – Main Control Board Relay Fault

Issue:

The E02 error code indicates that a relay on the control board has either failed or is malfunctioning, preventing the appliance from operating properly.

Possible Causes:

Electrical short in the board: A short circuit can occur on the control board, which disrupts the relay's function and causes the error.
Power surge or overvoltage: A sudden surge in electrical power or overvoltage can damage the control board components, leading to a malfunction.
Internal board damage: Physical or internal damage to the control board, whether due to wear and tear or external impact, can interfere with the relay's performance.

Solutions:

Start by turning off the appliance and disconnecting it from the power supply for about 30 seconds. This can sometimes reset the control board and clear the error.
If the error persists after restarting, it may be necessary to replace the control board. Consult with a qualified technician for a proper diagnosis and replacement, as working with electrical components requires precision and safety.

E03 – Main Control Board Relay Fault

Issue:

The E03 error code signals a malfunction in the control board’s relay, which prevents the dishwasher from activating certain functions or completing its cycle. This issue is similar to the E02 error but affects specific operational features of the dishwasher.

Possible Causes:

Relay malfunction: The relay within the control board may not be functioning correctly, causing the appliance to fail to respond to commands.
Defective control board: A faulty control board, often caused by age or wear, can prevent the proper communication and activation of the dishwasher’s components.
Electrical noise or spike: Electrical interference or power spikes can cause temporary damage or disruption to the control board's relays, leading to this error.

Solutions:

Reset the power by turning off the circuit breaker or disconnecting the power supply to the dishwasher for about 5 minutes. This can help clear any temporary errors and restore normal function.
If the error continues after resetting the power, replace the control board. If you're unsure about the replacement process, it’s advisable to seek assistance from a professional technician to ensure proper installation and safety.

E05 – Wash Arm Diverter Circuit Fault

Issue:

The E05 error code indicates a malfunction within the wash arm diverter system, which is responsible for directing water to different parts of the dishwasher. This issue can stem from either a fault with the motor or an electrical problem with the control board, preventing proper water distribution during the wash cycle.

Possible Causes:

Jammed diverter motor: If the diverter motor is obstructed or jammed, it may fail to operate correctly, disrupting the water flow and causing the error.
Defective wiring: Damaged or loose wiring connected to the diverter motor or control board can lead to electrical interruptions, preventing the system from functioning as intended.
Main control board error: A fault in the main control board can interfere with the signals sent to the diverter motor, resulting in an operational failure.

Solutions:

Reset the dishwasher by turning off the power and then restarting it. This can sometimes clear temporary faults and restore normal operation.
Inspect the diverter motor and wiring for any visible signs of damage or obstruction. Look for any blockages in the motor or loose, frayed wires that might be causing the issue.
If any components are found to be faulty, replace the damaged parts. This may include the diverter motor, wiring, or even the control board, depending on the nature of the fault.

E06 – Door Sensor Circuit Error

Issue:

The E06 error code appears when the dishwasher is unable to detect that the door is securely closed. This issue prevents the appliance from starting its wash cycle, as most dishwashers are designed to operate only when the door is fully latched.

Possible Causes:

Malfunctioning door latch sensor: The door latch sensor might be faulty, preventing it from accurately detecting whether the door is closed.
Loose wiring or sensor misalignment: If the sensor's wiring is loose or if the sensor is misaligned, it might fail to register that the door is shut properly.
Faulty control board: A malfunctioning control board could fail to interpret the signal from the door sensor correctly, leading to this error.

Solutions:

Reset the dishwasher by turning off the power for a few minutes, then restarting it. This can sometimes clear minor glitches and allow the system to function properly again.
Ensure the door is properly closed and latched. Double-check that nothing is blocking the door from sealing correctly, as an improperly closed door will trigger this error.
If the error continues to appear, replace the door sensor. If you’re unsure about replacing the part yourself, it’s recommended to contact a professional technician for assistance.

E07 – Zeolite Fan Motor Fault (CrystalDry)

Issue:

The E07 error code indicates a problem with the fan motor that powers the CrystalDry system, which is responsible for drying dishes efficiently by using zeolite minerals. If the fan motor is not functioning properly, the drying process will be impaired.

Possible Causes:

Failed fan motor: The most common cause of this issue is a failure of the fan motor itself, which may have worn out over time or experienced an internal malfunction.
Obstructed airflow: Dirt, debris, or other obstructions can block the fan’s airflow, preventing it from operating efficiently and leading to the error code.
Wiring issue to the fan circuit: Loose or damaged wiring connected to the fan motor can prevent it from receiving power, causing it to stop working.

Solutions:

Power reset the dishwasher by turning it off at the circuit breaker or unplugging it for several minutes. After restoring power, the system may reset itself, clearing any temporary issues.
Inspect and clear any obstructions from the fan housing and airflow pathway. Ensure that no debris, dust, or other blockages are preventing the fan from operating as it should.
If the fan motor is confirmed to be defective, replace the fan motor. It is recommended to consult a technician for assistance if you're not familiar with replacing motor components.

E09 – Internal Heater Fault (Heat Pump)

Issue:

The E09 error code indicates that the internal heating element within the heat pump is not functioning properly. This system is crucial for the dishwasher’s drying process and maintaining the required water temperature during cycles. If the heat pump isn’t working, the dishwasher will be unable to complete its cycle effectively.

Possible Causes:

Burnt-out heater coil: Over time, the heating element in the heat pump can burn out, losing its ability to heat water and air for drying, leading to this error.
Electrical fault in the pump: Issues such as a short circuit, loose connections, or damaged wiring in the heat pump assembly can interrupt the power supply to the heating element, causing the error code to appear.
Broken sensor reading: A malfunctioning sensor that monitors the temperature of the water or air inside the dishwasher could send incorrect readings, causing the system to fail to engage the heat pump properly.

Solutions:

Restart the dishwasher by turning it off and then on again. A simple reset can sometimes clear temporary issues and allow the system to start functioning correctly.
If the issue persists, the heat pump assembly may need to be replaced. The internal heating element or related components could be damaged, requiring professional assistance for replacement and repair.

E10 – Zeolite Chamber Heater Fault

Issue:

The E10 error code indicates that the heater in the CrystalDry chamber, which helps to dry the dishes by activating the zeolite minerals, is malfunctioning. If this heater is not working, the drying process will be significantly affected, leading to poorly dried dishes.

Possible Causes:

Faulty heater unit: The most common cause is a malfunction within the Zeolite chamber heater, which may be due to a damaged or worn-out heating element that no longer functions correctly.
Wiring issue: Loose, frayed, or disconnected wiring leading to the heater can prevent it from receiving power, resulting in the error code.
Sensor failure: A faulty sensor that monitors the temperature or humidity inside the CrystalDry chamber could be sending incorrect signals to the control board, preventing the heater from turning on.

Solutions:

Perform a power reset by turning off the dishwasher at the breaker or unplugging it for several minutes. After restoring power, the system may reset itself, and the error could clear if it was caused by a temporary glitch.
If the error persists, replace the Zeolite heater. If you're not familiar with replacing the part, it’s best to consult with a qualified technician to ensure the heater is properly replaced and functioning as it should.

E12 – Limescale Buildup in Heat Pump

Issue:

The E12 error code appears when limescale has accumulated in the heat pump, hindering its ability to function properly. Limescale buildup can restrict water flow and impair the heating system, causing inefficient washing and drying cycles.

Possible Causes:

Hard water usage without descaling: When hard water is used without periodic descaling, mineral deposits like calcium and magnesium can build up in the heat pump and other internal components, leading to this error.
Lack of softening salt in softener-enabled models: If your dishwasher is equipped with a water softener and you haven’t been replenishing the softening salt, this can lead to increased limescale buildup over time, especially in areas with very hard water.

Solutions:

Run a descaling cycle using a Bosch-approved dishwasher descaler. Follow the manufacturer’s instructions to remove limescale buildup and restore the heat pump's functionality.
For future prevention, ensure you use softening salt in softener-enabled models. This helps to reduce mineral deposits in the dishwasher and prevents limescale buildup in the heat pump and other components.

E14 – Flow Meter or Water Filling System Failure

Issue:

The E14 error code indicates that there is an issue with the water flow into the dishwasher. Either the water is not entering the appliance properly, or the flow meter is unable to detect the incoming water. This prevents the dishwasher from starting or completing its cycle as it requires an adequate water supply for washing.

Possible Causes:

Blocked or kinked inlet hose: If the inlet hose is clogged, kinked, or bent, water flow may be restricted, preventing the dishwasher from receiving the correct amount of water.
Clogged inlet screen or faulty flow meter: A blocked inlet screen can obstruct water from flowing into the dishwasher, while a malfunctioning flow meter might fail to register the amount of water coming in, triggering the error code.
Low water pressure: Insufficient water pressure in your home can also lead to an inability for the dishwasher to fill with water properly.

Solutions:

Inspect and straighten the inlet hose to ensure it’s not kinked, clogged, or obstructed in any way. Ensure it is properly connected and aligned to allow water to flow freely into the dishwasher.
Clean the inlet filter to remove any debris or buildup that might be blocking the water flow. A clean filter ensures that water can enter the dishwasher without obstruction.
If the flow meter is faulty or if the issue persists after cleaning, replace the flow meter. A professional technician may be needed to accurately diagnose and replace the flow meter if you're unfamiliar with the process.

E15 – Water Leak Detected in Base

Issue: The E15 error code is triggered when water collects in the base pan of the dishwasher, activating the anti-flood protection system. This system is designed to prevent water from overflowing onto the floor, but it can also cause the dishwasher to stop functioning if it detects a leak.

Possible Causes:

Leaking hose or seal: A damaged or worn-out hose or seal can allow water to leak into the base pan, triggering the anti-flood protection system.
Overfill or splash from internal spray: If the dishwasher is overfilled with water, or if there’s excessive splashing from the spray arms, water may spill over and collect in the base pan.
Dishwasher not level: If the dishwasher is not properly leveled, it can cause uneven water distribution, leading to leaks that trigger the anti-flood system.

Solutions:

Turn off the water supply and power to the dishwasher immediately to prevent further leakage or damage.
Tilt the dishwasher slightly to drain the water from the base pan. You may need to adjust the appliance’s position to help the water flow out.
Inspect and fix any leaks. Check hoses, seals, and internal spray components for damage or wear. Ensure the dishwasher is properly leveled before restarting the appliance to avoid further issues.

E16 / E17 – Water Inlet or Overfill Issue

Issue:

E16 indicates that water is not entering the dishwasher properly, which can prevent the cycle from starting.
E17 indicates that the dishwasher is overfilling with water, which can cause leaks or improper washing.

Both errors are related to issues with the water inlet system, either preventing the proper amount of water from entering or allowing too much water to flow into the dishwasher.

Possible Causes:

Blocked or bent inlet hose: If the inlet hose is blocked, kinked, or bent, it can restrict the flow of water into the dishwasher, leading to the E16 error. In contrast, if the hose is damaged or incorrectly installed, it may contribute to an overfill, triggering the E17 error.
Defective water inlet valve: A malfunctioning inlet valve may fail to open properly (E16) or may fail to close completely, causing water to continue filling the dishwasher, resulting in overfilling (E17).
Faulty water level sensor: The water level sensor detects the water inside the dishwasher. If the sensor is faulty, it may incorrectly signal the control board, either preventing water from entering (E16) or failing to detect an overfill (E17).

Solutions:

Open the water valve and check the inlet hose for any visible blockages, bends, or damage. Ensure that the hose is properly connected and not obstructed.
Replace the water inlet valve if it is found to be defective. Ensure it opens and closes correctly to regulate the water flow.
Inspect the water level sensor for any damage or malfunctions. If the sensor is faulty, it should be replaced to ensure accurate water level detection.

E18 – Low Water Level or Flow

Issue:

The E18 error code occurs when the dishwasher is not filling with water to the expected level. This can prevent the appliance from operating correctly, as it requires an adequate water supply to perform its cycles effectively.

Possible Causes:

Kinked or obstructed inlet hose: If the inlet hose is bent, kinked, or clogged, it may restrict the flow of water into the dishwasher, preventing it from reaching the required level.
Low water pressure (under 10 l/min): Insufficient water pressure can prevent the dishwasher from filling properly, causing the system to register a low water flow.
Partially open faucet: If the faucet supplying water to the dishwasher is not fully open, it can limit the water flow, leading to the E18 error.

Solutions:

Fully open the water valve to ensure that the dishwasher is receiving the maximum amount of water it needs.
Straighten the inlet hose and ensure there are no blockages or bends that could obstruct water flow.
Check your home's water pressure to ensure it meets the required level. If the pressure is low, you may need to consult a plumber to address any issues with the water supply.

E19 – Detergent Dispenser Solenoid Circuit Error

Issue:

The E19 error code indicates that the solenoid controlling the detergent dispenser is not functioning correctly. This solenoid is responsible for opening the detergent dispenser at the appropriate time during the wash cycle. If it fails, the detergent will not be dispensed, resulting in poor cleaning performance.

Possible Causes:

Wiring fault: A wiring issue, such as a loose or damaged connection, can prevent the solenoid from receiving the proper signal to open the detergent dispenser.
Defective solenoid: Over time, the solenoid itself may become faulty, either due to wear and tear or electrical failure, leading to the inability to control the detergent dispenser.
Control board issue: A malfunction in the control board can cause it to fail in sending the correct signals to the solenoid, preventing it from activating at the right time.

Solutions:

Reset the dishwasher by turning it off and on again. This can help reset any temporary issues that might have affected the solenoid’s functionality.
If the error persists, you may need to replace the detergent dispenser unit, which includes the solenoid. If you're unsure how to replace the dispenser, it’s recommended to seek help from a professional technician.

E20 – Heat Pump Internal Heater Error

Issue:

The E20 error code occurs when there is a heating failure within the heat pump circuit. The heat pump is responsible for maintaining the proper temperature during the washing and drying cycles. A failure in this component can lead to poor cleaning and drying performance.

Possible Causes:

Faulty heating element: A malfunctioning or damaged heating element within the heat pump may fail to heat water or air properly, causing the error.
Electrical fault in the control system: An issue within the electrical components or control system could prevent the heat pump from functioning correctly, leading to the failure of the internal heater.
Sensor misread: If the temperature or humidity sensor misreads the conditions inside the dishwasher, it could cause the control system to wrongly interpret the need for heating, triggering the error code.

Solutions:

Reset power to the dishwasher by turning it off and on again. A power reset may clear temporary issues and restore normal operation.
If the error persists, you may need to replace the heat pump assembly. This typically involves replacing the entire heat pump unit, including the heating element. It is recommended to contact a professional technician for this repair to ensure proper installation.

E21 – Blocked Heat Pump

Issue:

The E21 error code indicates that the circulation pump in the heat pump system is either blocked or not functioning correctly. The circulation pump is responsible for moving water through the dishwasher’s system to maintain the appropriate temperature during the wash and rinse cycles. If the pump is obstructed or faulty, the dishwasher will not perform as expected.

Possible Causes:

Debris blocking the pump: Foreign objects, food particles, or mineral buildup can obstruct the circulation pump, preventing it from operating correctly and leading to the error.
Motor failure: The motor that powers the circulation pump could fail due to electrical issues, wear and tear, or a malfunction, preventing the pump from circulating water properly.
Sensor miscommunication: A fault in the sensors that monitor pump function or water circulation could send incorrect signals to the control system, resulting in the E21 error.

Solutions:

Reset power to the dishwasher by turning it off and on again. This can sometimes clear minor glitches and reset the system to normal operation.
Inspect and clean the pump. Check for any blockages, debris, or buildup around the circulation pump. Ensure it is free from obstructions and that the motor is operating smoothly.
If cleaning the pump doesn’t resolve the issue, replace the circulation pump. If you're unsure how to proceed, it’s best to consult a professional technician to handle the replacement.

E22 – Dishwasher Filter Blocked

Issue:

The E22 error code appears when the dishwasher’s filter system is clogged with food particles, grease, or other residue, preventing proper water drainage and filtration. A blocked filter can lead to poor cleaning performance and water buildup within the dishwasher.

Possible Causes:

Infrequent filter cleaning: Over time, food particles, grease, and detergent buildup can accumulate in the filter, especially if it hasn’t been cleaned regularly.
Grease or hard residue buildup: Particularly greasy or hard-to-remove food particles can become stuck in the filter and accumulate over time, leading to blockages and restricting water flow.

Solutions:

Remove the filter from the bottom of the dishwasher and clean it thoroughly under warm water. Use a soft brush or sponge to scrub away any debris or buildup.
Clean the sump (the area beneath the filter) and the surrounding area to ensure there is no additional blockage. Check for food particles or other residues that may have fallen into the sump and are obstructing the water flow.
Reinstall the filter securely once it has been cleaned and ensure it is positioned correctly before using the dishwasher again. This will prevent future blockages and ensure optimal drainage.

E23 – Drain Pump Blocked or Faulty

Issue:

The E23 error code indicates that the dishwasher’s drain pump is unable to remove water from the appliance. The drain pump is responsible for pumping out water during and after the wash cycle. If it fails to operate correctly, water will remain in the bottom of the dishwasher, and the cycle cannot complete.

Possible Causes:

Clogged pump or impeller: The drain pump or its impeller may be clogged with debris, food particles, or other obstructions, preventing it from pumping out water.
Loose wiring: Wiring issues, such as loose or disconnected connections, can prevent the drain pump from receiving power, causing it to fail.
Pump motor failure: The motor that drives the pump could be faulty or burned out, preventing the pump from operating altogether.

Solutions:

Remove obstructions from the pump and impeller. Inspect the drain pump for any visible blockages or debris that might be preventing it from functioning properly. Clear away any foreign objects or buildup.
If the pump appears damaged or is still not operating after removing any blockages, replace the pump. If you’re unsure how to replace the pump, consider contacting a professional technician to ensure proper installation.

E24 – Dishwasher Not Draining

Issue:

The E24 error code indicates that the dishwasher is not draining properly, causing water to remain in the bottom of the tub after a wash cycle. This can affect the dishwasher’s performance and lead to standing water, which may result in foul odors or poor cleaning results.

Possible Causes:

Blocked drain filter: A clogged filter or debris blocking the drain filter can prevent the dishwasher from draining properly, trapping water in the tub.
Improperly installed drain hose: If the drain hose is kinked, bent, or installed incorrectly, it may restrict the flow of water, causing drainage issues.
Pump cover is loose or not sealed: A loose or improperly sealed pump cover can allow water to leak into the dishwasher's base, disrupting the draining process.

Solutions:

Clean the filter and pump area to remove any debris or food particles that could be blocking the drainage. Check the filter and sump area for any obstructions and clean them thoroughly.
Check and reposition the drain hose to ensure it is not kinked or obstructed. Make sure the hose is correctly installed and positioned to allow proper water flow.
Ensure the knockout plug in the garbage disposal (if connected) is removed. If the dishwasher is connected to a garbage disposal, the knockout plug must be removed to allow proper water drainage.

E25 – Drain Pump Cover Loose or Blocked

Issue:

The E25 error code occurs when the drain pump is either obstructed by debris or its cover is not securely fitted. This issue prevents the pump from functioning correctly, leading to poor drainage or failure to drain water from the dishwasher.

Possible Causes:

Foreign objects in the pump: Small items, food debris, or other obstructions may get lodged in the drain pump, preventing it from operating properly.
Loose or missing pump cover: If the pump cover is loose, missing, or improperly fitted, it can prevent the pump from working efficiently, which may result in drainage issues.

Solutions:

Remove the filter and pump cover. Start by removing the dishwasher’s filter to access the pump cover. Carefully remove the cover and inspect it for any debris or foreign objects that could be blocking the pump.
Remove debris and secure the cover. Clean out any debris or foreign objects from the pump and the surrounding area. Once the area is clear, securely replace the pump cover and ensure it is properly fitted.
Run a test cycle to verify that the pump is functioning correctly and that the dishwasher drains properly. This will confirm that the issue has been resolved.

E27 – Low Voltage Detected

Issue: The E27 error code indicates that the dishwasher is receiving insufficient power, which can cause it to malfunction or not operate at all. The appliance requires a stable and adequate voltage to function properly, and any dips or fluctuations in power can lead to this error.

Possible Causes:

Low incoming voltage from the power supply: The dishwasher may not be receiving the correct voltage due to issues with the electrical supply, such as fluctuations or voltage drops.
Shared or overloaded circuit: If the dishwasher is connected to a circuit that is overloaded or shared with other high-power appliances, it may not receive the proper voltage, triggering the E27 error.

Solutions:

Reset power to the dishwasher by turning it off and then back on. This can sometimes clear temporary power-related issues.
If the error recurs, have an electrician test the circuit and voltage. A qualified professional can check the electrical supply, ensuring that the dishwasher is receiving the correct voltage and that the circuit is not overloaded. They can also verify if there are any issues with the wiring or electrical components.

Bosch Dishwasher Troubleshooting Tips

To minimize errors and extend the life of your Bosch dishwasher, follow these maintenance tips:

Clean the filter weekly: Regularly cleaning the filter helps prevent blockages, which can lead to poor drainage and performance issues (E22). Make sure to remove any debris or food particles that may have accumulated.
Use Bosch-approved dishwasher descaler monthly: In areas with hard water, mineral buildup can reduce the efficiency of your dishwasher and lead to issues such as heating failures (E12). Running a descaling cycle once a month helps prevent limescale buildup and ensures proper function.
Inspect water lines regularly for kinks or blockages: Check the water inlet hose for any obstructions, kinks, or damage, as these can affect water flow (E14, E16–E18). Ensure that the hose is correctly installed and free from any blockages that could disrupt normal operation.
Use proper detergent and follow recommended quantities: Always use the recommended type and amount of detergent for your dishwasher. Using too much or the wrong type of detergent can trigger issues with the detergent dispenser solenoid (E19) and lead to improper cleaning results.
Keep the unit level to avoid leak-related issues: Ensure that the dishwasher is level, as an uneven unit can cause water to leak into the base (E15), triggering the anti-flood system. Use a spirit level to check the dishwasher’s position and adjust the feet if necessary.
Check your power supply and avoid plugging into overloaded circuits: Make sure that the dishwasher is plugged into a properly grounded outlet and not into an overloaded power circuit (E27). Overloaded circuits can lead to an insufficient power supply, which may cause the dishwasher to malfunction.

By following these simple yet effective tips, you can ensure that your Bosch dishwasher runs efficiently and lasts longer, reducing the likelihood of frequent errors and costly repairs.