Bosch Washer Error Codes: Causes & Fix

What does my Bosch washer error code mean?#

Reading and clearing Bosch codes#

When a fault hits, the cycle pauses and the display shows "E:" and two digits; the code stays until you turn the selector to OFF or unplug. The 300, 500, and 800 series (WAT, WAW, and WGA prefixes) share the same system, and 800-series units with Home Connect also show the code with a description in the app. Write it down first, because some codes only appear once and otherwise need diagnostic mode to retrieve. To force-clear after a repair, unplug five minutes and run a short Rinse/Spin — if the code stays gone, the fault was transient.

Bosch washer error-code reference#

Working the common ones#

E:18 (start here): this is the single most common Bosch code — roughly 45% of service calls — and it usually isn't the pump. Open the service flap at the bottom-left front, drain the emergency hose into a pan, unscrew the drain-filter cap, and clear out coins, lint, and hairpins; spin the pump impeller to confirm it turns freely and check the external hose for kinks. Only if the filter is clean and the pump spins does the pump or the internal sump hose become the suspect.

E:23 (the one to respect): the float in the base pan detected water, meaning a real internal leak — most often a torn door-boot gasket letting water out during spin, or a pump-seal or sump-hose leak. Don't reset and re-run; mop the base pan, run a short cycle watching for the source, and check the door gasket, pump housing, and dispenser channel.

E:02 and E:21: an E:02 fill fault is usually a closed valve, a triggered AquaStop hose (replace it if the red indicator shows — it can't be reset), or scaled inlet screens you can clean with vinegar. An E:21 means the board lost communication with the EcoSilence Drive inverter — reseat the six-pin motor connector behind the rear panel, and if it's secure and undamaged, the inverter module is the fault.

Codes that need a pro now#

Some codes shouldn't wait: E:23 with water on the floor risks electrical damage, E:21 with a burning smell means the motor inverter is cooking, any E-code that also trips your breaker suggests a short, and high board-level faults need Bosch's service tool. For everything else, the code plus the matching fix above gets you most of the way.

Repair or replace?#

The most common codes are free fixes — a drain-filter clean for E:18, a screen clean for E:02 — so a Bosch washer throwing codes is almost always worth keeping. Only an inverter module (E:21) or a heater is a real parts cost; a diagnostic visit and the stored code confirm the part before anything is ordered.

Frequently asked questions#

My Bosch washer shows E:18 after every wash — is the pump dead?#

Not necessarily — E:18 is the most common Bosch code and usually just means the drain filter is clogged, so clean it behind the bottom-left flap first. If the filter is clear and the pump impeller spins freely but E:18 keeps returning, then the pump is weakening or the internal sump hose is partly restricted.

Can I ignore a Bosch washer error code if the cycle still finishes?#

Some codes are warnings that let the cycle complete, like an oversuds condition, but others signal active damage and shouldn't be ignored. Never ignore E:23, because it means the base-pan float found water where it shouldn't be — an internal leak that needs finding before you run another load.

My Bosch washer showed a code then cleared itself — should I worry?#

A single occurrence can be transient, like a brief low-water-pressure moment or a power flicker, and may not return. But if the same code comes back within a week, the underlying cause is developing and will worsen, so it's worth diagnosing while it's still intermittent.