Most common error codes in Bosch dishwashers: a clear guide

Why Bosch dishwashers display error codes

Bosch dishwashers rarely fail without warning. The display—or the combination of lights and symbols—acts like a basic report: when a code appears the machine is pointing to an area where water, temperature, drainage or electronics are out of expected range. These codes are clues, not exact part diagnoses. Reading them correctly helps avoid unnecessary disassembly and speeds up repair.

If you have a problem with your dishwasher you can use our free error code finder to identify and fix many errors quickly and effectively.

How Bosch interprets fault codes

Most Bosch models use a convention of the letter E followed by one or two digits to group faults into families (electrical, hydraulic, control, etc.). The same code can sometimes have different causes depending on the model series (built-in, compact, freestanding) or the internal architecture, so the code guides the diagnosis but context is decisive.

Most common error codes and what they mean

• E01 / E09 — Heating or heating circuit failure

  What it indicates: Water is not reaching the expected temperature or the heating element/circuit is malfunctioning. Causes include insufficient water level, defective heater, limescale buildup, or wiring/board faults.

  What to check first: water level, inlet and filters, visible limescale, reset cycle. Severity: medium to high (may require component replacement).

• E02 / E11 — Temperature (NTC) sensor fault

  What it indicates: The temperature probe sends erratic or wrong readings, causing confused cycles or unexpected stops. Causes: defective sensor, loose connector, or intermittent readings to the control board.

  What to check first: probe connection, wiring, and continuity; if readings are inconsistent, the probe or board may need replacement. Severity: medium.

• E03 / E14 / E18 — Filling / flow meter / inlet problems

  What it indicates: The dishwasher cannot fill to the expected level or the flow is not being measured correctly. Causes include closed tap, bent/kinked hose, blocked inlet filter, faulty inlet valve, activated Aquastop, or a failed flow meter.

  What to check first: household tap, supply hose condition, inlet filter and mesh, Aquastop device. If water is present but the machine still reports an error, suspect the flow meter or valve. Severity: medium.

• E15 — Water detected in the base / overflow protection

  What it indicates: The float/microswitch in the lower tray detects water or an overflow condition and the machine stops to prevent damage. Causes: actual leak (hose, seal, cracked component), condensate, or a small amount of water triggering the sensor.

  What to check first: remove lower kickplate, dry the base tray thoroughly, inspect hoses/seals for leaks. If the error persists after drying, locate the leak or consult a technician. Severity: high.

• E16 / E17 — Inlet valve / overfill problem

  What it indicates: The solenoid valve does not open or close correctly, or level control is faulty, risking overfill or erratic filling. Causes: blocked valve, stuck solenoid, Aquastop activation, or control fault.

  What to check first: inlet valve, wiring, and inlet filter; also check for Aquastop trip. Severity: high.

• E20 / E21 / E22 — Circulation / wash pump faults

  What it indicates: The wash motor/pump does not rotate properly or is obstructed, reducing spray pressure and cleaning performance. Causes: damaged motor, coil short, worn bearings, blocked impeller, or capacitor/board issues.

  What to check first: unusual buzzing, poor spray arm rotation, foreign objects in pump area. If mechanical blockage is cleared but motor won’t run, the pump or electronics may need service. Severity: high.

• E23 / E24 / E25 — Drainage / drain pump blocked

  What it indicates: The dishwasher cannot empty at expected speed or the drain pump is jammed. Causes: clogged hose, sink trap blockage, foreign object in pump, or damaged pump impeller.

  What to check first: clean filters, free the drain hose, check sink trap, inspect and clear pump area. Severity: medium to high (if pump damaged).

• E26 — Water switch / float switch failure

  What it indicates: The float or microswitch that detects base water is activated incorrectly or has failed. Causes: stuck float, clogged lower tray, damaged switch or wiring.

  What to check first: dry and clean the base tray, free any obstructions to float movement, test float/switch operation. Severity: medium.

• E27 — Low or unstable mains voltage

  What it indicates: Electrical supply outside acceptable limits. Causes: mains instability, poor connection, or defective internal power supply components.

  What to check first: verify plug and supply, try a different outlet, check other appliances. If persistent, technician required. Severity: medium.

• E28 — Turbidity / water dirtiness sensor problem

  What it indicates: The optical/ turbidity sensor reads incorrectly, affecting rinse decisions. Causes: dirty sensor, misadjustment, or sensor failure.

  What to check first: clean sensor area, check wiring; if readings remain incorrect, sensor replacement may be needed. Severity: medium.

• E31 — Heat pump / advanced heating fault

  What it indicates: Fault in thermal assembly, heat pump or heating management system. Causes: internal heating components, control faults, or safety thermistors activated.

  What to check first: basic heating checks (water level, flow) and then call service for heat pump/assembly diagnostics. Severity: high.

• E06 / E07 / E08 / E10 / E13 — Miscellaneous (door latch, drying, pressure, overheating, inlet temp)

  What they indicate: typical practical faults include a faulty door latch (E06), drying or final temperature issues (E07), insufficient wash pressure or foam issues (E08), heater overheating often due to limescale or poor flow (E10), and inlet water temperature too high (E13).

  What to check first: ensure door closes properly, check for excessive detergent/foam, test inlet water temperature and flow, and inspect heating element for scale. Severity: varies from low to high depending on the specific fault.

Why the same code can mean different things

Codes describe the area where the anomaly was detected, not necessarily the exact failing part. For example, E03 typically means the machine cannot fill, while E16 more specifically implicates the inlet valve. Externally both may show as “no water,” yet one is a supply/installation issue and the other is a component failure. Built-in installation (kinked hoses, crushed tubing behind cabinets) or house supply problems (low pressure) often mimic internal faults.

Troubleshooting: practical checks before calling service

1. Reset the dishwasher (turn off, wait 1–2 minutes, restart) to rule out transient errors.
2. Check the water supply tap and the inlet hose for kinks or obstruction.
3. Inspect and clean inlet filter and mesh; check Aquastop if fitted.
4. Clean basket filters and remove debris from pump area; inspect drain hose and sink trap.
5. Dry the base tray under the kickplate and ensure the float moves freely (for E15/E26).
6. Check door latch and microswitch operation for secure closing.
7. If heating-related: verify that the machine has enough water, check for heavy limescale, and look for strange sounds from the pump/motor.
8. If a code persists after these checks, note the exact code, any sounds, and when it appears—this information speeds professional diagnosis.

When to call a technician

Call service when:

• The error is a high-severity code (e.g., E15, E16, E20, E31) indicating leaks, inlet valve failure, pump/motor failure, or heat-pump/major heating faults.
• Basic checks (supply, hoses, filters, drying the base) do not clear the error.
• There are clear signs of electrical problems (burn marks, repeated low-voltage warnings, or persistent control-module faults).
• The machine emits odd noises followed by a code or does not complete a program despite visible remedies.

Technicians can test components (flow meter, NTC probe, pump coils, board) and perform safe interventions that are not advisable for household DIY.

Final notes

Bosch error codes are diagnostic clues: they narrow the search to an area (heating, inlet, drainage, sensors, electronics) but do not always name the failed part. Start with simple, visible checks—supply, hoses, filters, and drying the base—and use the error code to guide the next steps. If the fault persists after basic troubleshooting, a qualified technician will save time and prevent incorrect part replacements.

Remember: our free error code finder can help interpret codes and suggest tailored fixes for your specific model.