Bosch Dishwasher Error Codes — Complete Fix Guide

Bosch Dishwasher Error Code Reference

Bosch dishwashers across the 100, 300, 500, 800, and Benchmark series share the same E-prefix fault dictionary at the control-board level. Older models (pre-2015) flash error codes via the rinse-aid or clean light blink pattern. Newer models with displays show the code directly.

The 5 Most Common Bosch Dishwasher Faults

E15 — Water in the Base / Aquastop Tripped (most common)

E15 is the #1 callback. The aquastop is a float switch in the base pan; any water in the pan raises the float and trips the controller into permanent leak-protection mode (constant drain pump operation, can’t start a cycle).

Fix workflow:

1. Pull the dishwasher out from under the counter. Disconnect water and drain (have a towel ready).
2. Tip the dishwasher 45° toward the front and drain any water from the base pan into a shallow tray. Towel-dry the pan completely.
3. Re-install with the front feet leveled. Run a short rinse cycle. If E15 doesn’t return, the leak was a one-time event (overfill, briefly clogged drain, etc.).
4. If E15 returns within one cycle, you have an active leak. Common sources: door seal (perished), pump hose clamp (loose), heater gasket (corroded), or tub crack (rare). Find and fix.

The float switch itself rarely fails — about 95% of E15s are real water, not a sensor fault.

E22 — Filter Clogged

The sump filter at the bottom of the tub needs cleaning. Bosch’s design has 2-3 nested mesh filters that catch food debris.

1. Pull the lower rack out.
2. Twist the cylindrical filter assembly counter-clockwise to unlock. Lift out.
3. Disassemble the nested mesh elements. Rinse under hot water. A toothbrush helps with stuck food bits.
4. Re-install in the reverse order. Twist clockwise to lock.

If E22 returns immediately after cleaning, the wash-pump impeller is blocked (different fix: pull the impeller cover at the sump base, clear debris).

E24 — Drain Hose Blocked

The drain hose from the dishwasher to the under-sink standpipe is blocked. Common spots:

• High loop missing (drain hose must rise to ~32 in then drop) — water back-siphons and clogs over time.
• Air gap (at the sink top, if installed) is clogged with food debris — unscrew the cap and clean.
• Standpipe inside the cabinet is reduced/restricted by buildup.

Pull the hose at both ends and run water through it. If flow is reduced, replace.

E01 — Control / Electronics Fault

Generic “the control board threw an exception” code. Workflow:

1. Power off at the breaker for 5 minutes (not just unplug — Bosch boards retain state for 60s).
2. Power back on. If E01 doesn’t return, it was a one-time event.
3. If E01 returns, open the door panel (six Torx T20 screws on the top) and inspect the ribbon cable + power-board connectors. Re-seat both.
4. If E01 persists after re-seat, the main power board has failed (~$220-$380 part).

E02 — Heater NTC Sensor Fault

The water temperature sensor at the sump has gone open or shorted. It’s a thermistor — same diagnosis flow as the LG fridge / Mitsubishi mini-split sensor swap: pull the connector, measure resistance, expect ~10K ohms at 25°C, replace if outside range.

Replacement NTC sensors are ~$15-$25 and a 15-minute job. Don’t replace the whole heater assembly first.

Parts That May Need Replacement {#parts}

Technician Tips

• Bosch dishwashers have a “tilt sensor” anti-shipping feature. Units shipped with the lock screw still engaged will throw spurious errors. Look for a small Phillips screw under the front kickplate marked with a sticker — remove it on first install.
• The aquastop solenoid is in the inlet hose connector, not at the dishwasher. Replacing the dishwasher’s inlet hose without ordering the correct aquastop assembly = E15 on first cycle.
• For chronic E22 / E21 in households with hard water: descale the dishwasher monthly with citric acid (1 cup citric acid in an empty dishwasher, hot cycle). Buildup on the wash impeller throws drain-cycle errors first.
• The “Service” menu (hold Power + Regenerate together for 5 seconds on most newer models) shows the last 10 fault codes with timestamps. Useful for “what happened last week” diagnostics.

Common Code Combinations

• E15 → E24: leak triggered aquastop, but the drain pump can’t clear because the hose is also blocked. Fix drain first.
• E22 → E21: clogged filter caused the wash pump to overload and trip. Clean filter, reset, retest.
• E02 → E11 → E12: sensor wiring intermittent, board reads wildly different temps. Replace sensor + wiring harness.

If errors return within 48 hours of clearing them, the underlying fault is active — not transient. Schedule the next-step diagnostic instead of resetting again.

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