Bosch dishwasher error codes — comprehensive guide

Below I’ll explain the most common Bosch dishwasher error codes, what they mean, likely causes, step-by-step diagnostics and fixes you can try safely, how to reset the machine, and when to call Bosch or a repair tech. I’ll cite Bosch’s official guidance plus trusted appliance repair sources for the load-bearing items so you can verify specifics for your model. Major models are from the 100, 300, 500, 800, and Benchmark series.

Quick reference (most common codes)

• E15 — water detected in the base / anti-flood activated (leak).
• E16 / E17 / E18 — water fill / flow problem: water level too low, supply or inlet issue, or filling system fault.
• E19 — detergent dispenser / solenoid circuit fault (on some models).
• E20 / E21 — heating / heat-pump / internal heater faults (model dependent).
• E23 / E24 / E25 — drainage problem (blocked drain filter, blocked drain pump, or pump cover loose/missing).
• E01 / E02 / E03 / E04 / E05 — control board / power module failures (require specialist attention).

Safety first — read this before you poke around

1. Turn off power (unplug or switch off the breaker) and shut off the water supply before removing panels or inspecting hoses.
2. Only do internal inspections (pumps, wiring, underside) if you are comfortable and confident — otherwise call a pro.
3. If the error indicates a leak (E15) and you see water under the machine, remove the dishwasher from cabinetry only if it’s safe and you know how — otherwise call a technician.

Detailed troubleshooting & fixes (step-by-step)

E15 — Leak / water in base (anti-flood / watertap)

What it means: The base pan/flood sensor detected water and the appliance blocked water intake.
Likely causes: Door gasket leak, loose hose/clamp, cracked inlet valve, faulty pump seal, or water pooling from previous overflows.
DIY steps:

1. Turn off water and power. Remove lower kickplate and inspect base pan for water. Dry it with towels/vacuum.
2. Look for obvious leaks: inlet hose connections, pump seals, door gasket. Tighten clamps; reseat hoses.
3. If you removed water and the sensor still reads flooded, the float or flood sensor may be stuck — gently dry and check for free movement.
4. After repairs/drying, restore power and run a short test cycle. If E15 returns, stop and call Bosch/technician — internal leak source likely.

E16 / E17 / E18 — Fill / low water / water flow issues

What it means: Water isn't entering properly or measured water flow is too low. E18 commonly shows low water level or drainage/pumping issues depending on model.
Likely causes: Kinked inlet hose, closed supply valve, clogged inlet filter/strainer, faulty water inlet valve, or flow meter failure.
DIY steps:

1. Ensure the water supply valve is fully open and there’s normal household water pressure.
2. Inspect the inlet hose for kinks; disconnect and check the aerator/strainer where hose connects to valve — clean debris.
3. Check the dishwasher inlet valve electrically only if you are comfortable; otherwise call a pro.
4. If code persists after ensuring supply and cleaning, the flow sensor or inlet valve may need replacement.

E19 — Detergent dispenser/solenoid circuit fault

What it means: The control detected a problem with the detergent dispenser actuator/solenoid or its circuit.
DIY steps:

1. Reset power (cut power 30s) — sometimes clears transient fault.
2. Inspect dispenser for obstructions or damage.
3. If the solenoid or wiring looks damaged, call service — electrical replacement likely required.

E20 / E21 — Heating / heat pump / internal heater

What it means: Heating element or internal heater/heat-pump fault. Machine may not reach wash temperature.
Likely causes: Faulty heating element, temp sensor (NTC), relay on control board, or heat pump component failure on hybrid models.
DIY steps:

1. Reset power and run diagnostic/heated cycle. If still present, stop.
2. Measuring heater resistance and checking NTC requires multimeter skills; if unsure, call a technician.

E23 / E24 / E25 — Drainage / pump blocked / pump cover loose

What it means: Drain path or pump is blocked OR the drain pump cover is loose/missing (E25 specifically mentions pump cover). E24/E25 are commonly drainage errors.
Likely causes: Food debris, glass, eggshells, limpets jamming the pump, blocked filters, foreign objects in pump impeller, or loose pump cover.
DIY steps:

1. Turn off power. Remove lower rack and the filter assembly (follow manual). Inspect and clean filters and sump area.
2. Remove pump cover (usually beneath filter) and inspect impeller. Remove any debris (careful with sharp glass).
3. Check drain hose for kinks and the connection to the household drain or garbage disposal — ensure trap isn’t clogged.
4. Tighten/reinstall drain pump cover correctly. Reassemble and test. If pump hums but won't pump, pump may need replacement.

E01 / E02 / E03 / E04 / E05 — Control / power module failure

What it means: Indications of control board or power module failure; these typically require specialized repair or replacement. Bosch recommends calling service.
Action: Power-cycle (turn breaker off 30s) — if code persists, do not attempt complex electrical repairs if inexperienced; call Bosch/qualified technician.

General reset procedure (safe first step)

1. Turn off the dishwasher at the circuit breaker or unplug it.
2. Wait 30 seconds (some Bosch pages recommend ~30s).
3. Restore power and start a short cycle to see if code returns.
   If the error persists after reset and the above basic checks, proceed to the specific troubleshooting steps for that code.

When to call Bosch or a pro (short list)

• E15 returns after drying and simple checks → possible internal leak component failure.
• Drain pump replaced or cleaned but code persists or pump hums → pump motor or control issue.
• Control board / E0x codes → technician required.
• You’re not comfortable working on electrical components (heaters, inlet valve wiring, control board) — call a pro.

Bosch service line (US) is 1-800-944-2904 ; follow your local Bosch support contact for warranty/authorized repairs.

Preventive maintenance to avoid many error codes

• Clean the filter and sump monthly (prevents E24/E25 drainage faults).
• Scrape large food debris before loading; avoid large bones, glass shards, and egg shells that can jam pumps.
• Ensure dishwasher is level and door gasket intact to avoid leaks (E15).
• Replace cracked/old inlet hoses and check hose clamps once a year.
• Run a cleaning cycle with dishwasher cleaner every 1–3 months.

Model differences & manuals

Bosch uses similar codes across many models, but meanings and code notation can vary by series (e.g., E-codes vs. flashing LEDs). Always check your exact model’s owner manual or Bosch’s online support pages for model-specific guidance. If an error code shown on your display isn't listed in your manual, Bosch’s site and support team should be your source.

Quick troubleshooting checklist (printable)

1. Turn off power + water.
2. For E15: dry basin, inspect hoses/gasket, test for leaks.
3. For E18/E16: check water supply valve, inlet hose, inlet strainer.
4. For E24/E25: clean filters, remove debris from pump impeller, check drain hose/disposal.
5. Reset power (30s) and test.
6. If unresolved and code is E0x or returns repeatedly, call Bosch/tech.

Top official & trusted references

• Bosch official error code pages and self-help.
• Bosch E25 / pump guidance.