Bosch 300/500/800 Series front-load washer: field service manual

Covers: Bosch 24-inch compact and 27-inch 300, 500 and 800 Series front-loaders sold in the US (series names only).

Single sourceBrands: Bosch6 components

Bosch front-loaders use a European-style chassis with an electronic module, an analog pressure sensor, a door lock, a drain pump behind a front service cover, and AquaStop anti-flood protection on many models (inlet hose with safety valve plus a base-pan float switch). Codes appear as E## or F## depending on generation.

Safety first

Unplug before service.
Water at the pump cap may be hot.

How it works

Start: the door locks (E16/F16 if not locked).

Fill: water enters through the AquaStop hose valve and the inlet valve; the analog pressure sensor measures level; slow fill gives E17/F17 on many models.

Wash: tumble with heater and NTC; heating time faults E19/F19, unexpected heating E20/F20.

Drain: pump behind the front service cover; drain fault E18/F18.

AquaStop: water in the base pan lifts a float, the pump runs and fill stops; shows E23/F23.

Spin: imbalance checks, then ramp to selected speed.

Components & tests

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Official manufacturer documentation

Always confirm values against the tech sheet for the exact model.

OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work. © 2026 OnCall Tech. Original content; not a reproduction of any manufacturer document.Generic part photos (not of this brand): Front-load washer and dryer pair in a home laundry room by Curtis Adams, Pexels License

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