Bosch Washer F9 Error Code: Causes and Fixes

Editorially reviewedUpdated 2026-02-20

Quick answer: Drain performance low

What you’ll notice

Drain cycle exceeds expected duration; machine judges drain performance inadequate.

Bosch Washer Code F9 high severity
Bosch models: Bosch front-load washers (WAx/WGx in Europe; 300/500/800 series in North America) have a two-part filter: a flat mesh pre-filter and a cylindrical coin-trap, both behind the lower-front service flap. The EcoSilence brushless motor runs quietly — lower vibration than typical is normal, not a fault.

Common causes

  • Partially blocked pump filter reducing flow
  • Drain hose routed too high, increasing back-pressure
  • Pump impeller starting to wear

Step-by-step fix

  1. Clean the pump filter (see OE steps above).
  2. Ensure the drain hose peak is no higher than 100 cm from the floor.
  3. Run a drain-only cycle and listen for the pump — a healthy pump sounds steady, a worn one may pulse or whine.

Tools you may need

Shallow traySmall brush

Prevention

  • Clean the filter monthly.
  • Do not route the drain hose higher than specified in the installation manual.

When to stop DIY

If drain performance is slow even after clearing the filter, the pump is wearing and should be replaced before it fails completely.

FAQ

What does F9 mean on Bosch washer?

F9 usually indicates: Drain performance low.

Can I keep using the appliance with F9?

Use caution. Severity is high. If drain performance is slow even after clearing the filter, the pump is wearing and should be replaced before it fails completely.

How long does this fix usually take?

Typical first-pass troubleshooting takes 10–20 minutes.