E04 — Water flow / flow meter fault
Per Bosch's official US error-code page, E04 means the appliance has detected faulty (heater) electronics during its self-test.
- Keep using it?
- Yes, with caution
- DIY difficulty
- Moderate
- Typical cost
- $30-70
- Verified against
- bosch-home.com ↗
The fix
Flow meter (turbidity/flow sensor)
Water flow sensor / flow meter fault
Diagnose first: Control board not seeing expected pulses from the flow meter; sometimes a debris-jammed impeller.
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How to fix it
- Shut off the water and disconnect the inlet hose at the dishwasher.
- Clean the inlet screen with a brush and rinse.
- Verify hose is not kinked behind the unit during reinstall.
- Check house water pressure (should be 20-120 psi).
- If flow meter is faulty, replace the inlet hose assembly (AquaStop) or sump flow meter per model.
Why it happens
Typical signs: Cycle pauses early in fill · Display shows E04 · Reduced spray pressure
- Clogged inlet screen Screen at the inlet valve is blocked with debris from supply line.
- Low water pressure House pressure below the 20 psi Bosch minimum.
- Flow meter fault Hall-effect impeller in the AquaStop or sump is stuck or failed.
- Kinked supply hose Hose pinched behind the unit reducing fill rate.
Other parts sometimes needed
If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.
- Bosch AquaStop inlet hose Common replacementAmazon →
More Bosch dishwasher codes
Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: bosch-home.com.