Bosch Washing Machine Error Codes Explained – Fix E18, E17, E21 & More
Posted by KGA SUPPLIES on 23rd Mar 2026
Bosch Washing Machine Error Codes – Full Guide
If your Bosch washing machine is showing an error code, this guide explains exactly what it means — and how to fix it.
Many Bosch faults are simple issues like blockages or water supply problems, meaning you can often fix them yourself without paying for an engineer.
? Common Bosch Error Codes (Most Searched)
❌ E18 / F18 – Not Draining
Meaning: Water is not draining from the machine.
Causes:
- Blocked pump filter
- Kinked or blocked hose
- Faulty drain pump
Fix:
- Clean pump filter
- Check hose for obstructions
? One of the most common Bosch faults — often an easy fix.
❌ E17 / F17 – Water Fill Issue
Meaning: The machine is not filling with water.
Causes:
- Water tap closed
- Low pressure
- Blocked inlet valve
Fix:
- Open tap fully
- Clean inlet filter
❌ E21 / F21 – Motor Error
Meaning: The drum cannot rotate properly.
Causes:
- Blocked drum
- Worn carbon brushes
- Faulty motor
Fix:
- Check drum spins freely
- Replace motor brushes if worn
❌ E23 / F23 – Leak Detected
Meaning: Water detected in the base of the machine.
Causes:
- Internal leak
- Loose hose
- Seal failure
⚠️ Important: Turn off appliance and inspect immediately.
? Full Bosch Error Code List (A–Z)
? Door & Lock Errors
❌ E16 / F16 – Door Not Closed
Door not shut properly or faulty door lock.
❌ E42 / E43 – Door Unlocking Issue
Door mechanism jammed or control fault.
❌ E44 – Door Open During Cycle
Safety system triggered.
❌ E47 / E48 – Door Lock Electronics Failure
Fault in lock circuit.
? Water Supply & Flow Errors
❌ E17 / F17 – Water Fill Issue
Tap closed, low pressure, or blocked inlet.
❌ E28 – Flow Sensor Error
Incorrect water flow detection.
❌ E29 – Low Water Pressure
Restricted inlet or closed tap.
❌ NO – Water Not Entering
Similar to E17 (basic models).
? Drainage & Pump Errors
❌ E18 / F18 – Not Draining
Blocked filter or faulty pump.
❌ E24 – Pump Failure
Damaged or obstructed pump.
❌ E25 – Pump Blocked
Debris stuck in impeller.
? Heating & Temperature Errors
❌ E19 / F19 – Heating Too Slow
Faulty element or temperature sensor.
❌ E20 / F20 – Unexpected Heating
Control board issue.
❌ E30 – Heating Sensor Issue
Defective NTC sensor.
❌ E60–E69 – Heating Circuit Fault
Multiple heating-related issues depending on model.
⚙️ Sensors & Internal Faults
❌ E26 – Pressure Sensor Fault
Incorrect water level detection.
❌ E27 – Door Sensor Fault
Latch or sensor issue.
❌ E38 – Blocked Pressure Chamber
Requires cleaning.
? Leak & Safety Errors
❌ E22 – AquaStop Activated
Water detected in base.
❌ E23 / F23 – Leak Sensor Triggered
Machine leaking or flooded.
❌ E36 – AquaStop Failure
Fault with hose or leak system.
❌ E37 – Overfilling Detected
Faulty valve or pressure switch.
⚡ Motor & Mechanical Errors
❌ E21 / F21 – Motor Error
Blocked drum or worn brushes.
❌ E50 / F50 – Motor Fault
Tachogenerator or motor driver issue.
❌ F43 – Drum Not Turning
Motor jammed or worn components.
? Electronics & Software Errors
❌ E45 – Communication Error
Control module fault.
❌ E90–E92 – Software Fault
PCB communication issue.
? Other Indicators
? CL / CHILD – Child Lock Active
Hold start button for 5 seconds to deactivate.
? END Flashing
Programme finished or possible drain issue.
? When Should You Replace a Part?
If:
- The same error keeps returning
- The machine stops mid-cycle
- Resetting doesn’t fix the issue
…it’s likely a component needs replacing.
Common Bosch spare parts:
- Drain pumps
- Heating elements
- Door locks
- Sensors
? Replacing parts is often far cheaper than replacing the appliance.
?️ Need Bosch Spare Parts Fast?
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Browse Bosch washing machine parts today.
? Pro Tip
Always:
- Turn off power before inspecting
- Check filters and hoses first
- Confirm the exact error code
A simple fix could save you £100+.