Diagnose it. Fix it. Or bin it with confidence.
Bosch Complete Fault Diagnosis Guide
Price: $12.95
For Bosch Washer, Dryer and Dishwasher Owners
Bosch has one of the strongest reputations in home appliances — German engineering, quiet operation, and genuine longevity. But Bosch appliances have their own fault codes, their own known weak points, and their own repair economics. They’re also more repairable than most brands, which means a proper diagnostic guide is worth more than it would be for a budget machine.
This guide covers Bosch washers, dryers, and dishwashers across the Series 2, Series 4, Series 6, and Series 8 ranges.
Common Bosch Problems
Bosch faults cluster around a few patterns:
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Dishwasher not draining (E24/E25) — the most common Bosch fault. Fine-mesh filters clog readily, and drain pumps fail.
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Washing machine motor faults (E21) — on Series 2 and 4, this is often worn carbon brushes. On Series 6 and 8, it’s more often the EcoSilence Drive control board.
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Door lock faults (E16) — preventing the machine from starting.
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Flood protection activation (E15/E23) — Bosch’s flood detection system is more sensitive than most, and a small leak can trigger it.
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Dryer not heating — element or thermistor on vented and condenser models; sealed system fault on heat pump models.
Bosch Fault Codes Explained
Bosch uses E-codes on older models and F-codes on newer models, with identical numbers:
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E18 / F18 — Drain fault
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E17 / F17 — Water inlet fault
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E16 / F16 — Door lock fault
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E21 / F21 — Motor fault
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E23 / F23 — Flood protection activated
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E24 / F24 — Dishwasher drain fault
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E15 / F15 — Flood protection activated
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E09 / F09 — Dishwasher heating fault
The guide includes the full code table with meanings, causes, and diagnostic sections.
Major Diagnostic Areas Covered
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Carbon brush replacement for Series 2 and Series 4 motors
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EcoSilence Drive diagnosis for Series 6 and Series 8 — control board testing
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Drain pump and filter maintenance across all ranges
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Door lock and interlock testing
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Flood protection system diagnosis — locating the leak that triggered the code
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Dryer heating circuit testing including heat pump assessment
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Dishwasher drain and cleaning faults
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Model-specific notes across all four Series ranges
What the Complete Guide Covers
A full 25-page diagnostic reference covering washers, dryers, and dishwashers across the Bosch range. Includes a symptom flowchart, complete fault code library (E and F code equivalents), step-by-step multimeter testing, replacement procedures, a repair cost reference, and consumer rights guidance for the UK, EU, and other regions.
Repair vs Replacement
Bosch appliances typically last 10 to 15 years. The high replacement cost changes the repair calculus significantly — repairs that wouldn’t make sense on a budget machine are often worth doing on a Bosch.
A $45 drain pump on a $600 washer is obviously worth it. But even a $150 motor control board on a 6-year-old Series 6 is justified, because the machine has years of service left. The guide gives you the threshold for each fault.
Frequently Asked Questions
My Bosch dishwasher shows E24. What does that mean?
E24 means the dishwasher can’t drain. Check the filter first — Bosch filters are fine-mesh and clog more readily than most brands. Remove it from the centre of the dishwasher floor, clean it thoroughly, and clear the sump area.
What’s the difference between E18 and E24?
E18 is a washing machine drain fault. E24 is a dishwasher drain fault. The number differs because the appliance differs, but the diagnostic logic is similar — check the filter and pump.
My Bosch washer shows E21. Is it the motor or the brushes?
On Series 2 and Series 4, it’s usually worn carbon brushes — a $10 to $20 part. On Series 6 and 8, it’s more often the EcoSilence Drive control board. The guide explains how to tell the difference.
Is flood protection (E15/E23) serious?
It means water has leaked inside the machine. The system has shut off the water supply to prevent damage. You need to find and fix the leak before resetting. The guide walks through the likely sources.
How do I find my Bosch model number?
It’s on a rating plate inside the door, on the back of the appliance, or behind the kick plate.
You can also consult Bosch’s official support resources for product information, manuals and troubleshooting information.
Get the Complete Guide
Bosch fault codes look simple but the diagnostic paths behind them aren’t. This guide covers every common E and F code, tells you what to test, and gives you the repair-or-replace answer.
[Get the Bosch Complete Fault Diagnosis Guide — $12.95 →]
Related single-fault guides:
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Dishwasher Not Draining — $7.95
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Dishwasher Not Cleaning Dishes — $7.95