Bosch dishwashers are known for their performance and efficiency, which is why they are widely used in both residential and commercial kitchens. Like all modern appliances, Bosch dishwashers include a built-in diagnostic system that displays error codes when something isn’t working properly.
This guide explains what Bosch dishwasher error codes mean, why they appear, what you can safely check at home, how to reset your Bosch dishwasher, and when it’s time to call a professional technician.
Where Bosch Dishwasher Error Codes Appear
Bosch dishwasher error codes appear on the digital display panel when the unit detects a fault.
- Codes may show during filling, washing, draining, or heating
- Some errors stop the cycle to prevent leaks or overheating
- Most Bosch dishwasher error codes begin with the letter E followed by a number
Always note the error code before resetting or turning off the dishwasher.
Bosch Dishwasher Error Codes Explained
E1 / E2 – Temperature Sensor Error
This error indicates a problem with the temperature sensor (thermistor).
Why it happens:
- Faulty thermistor
- Wiring or control issue
What you can do:
If the error returns, the sensor usually requires professional testing or replacement.
E4 – Water Fill Error
This error means the dishwasher is not filling with water properly.
Why it happens:
- Water supply turned off
- Low water pressure
- Scale buildup or sensor issue
What you can do:
- Make sure the water supply valve is fully open
- Check the inlet hose for kinks
If the error persists, internal components may need service.
E5 – Overflow Error
E5 appears when the dishwasher detects too much water inside the unit.
Why it happens:
- Inlet valve not closing
- Float switch issue
What you can do:
- Turn off the dishwasher
- Shut off the water supply
- Reset the unit
Repeated overflow errors should be handled by a technician to prevent leaks.
E6 – AquaSensor Error
This error indicates a problem with the AquaSensor, which monitors water cleanliness and turbidity.
Why it happens:
- Faulty AquaSensor
- Wiring or control issue
What you can do:
- This error usually requires professional repair or sensor replacement
E9 – Heating Element Error
E9 means there is a problem with the dishwasher’s heating system.
Why it happens:
- Failed heating element
- Heating circuit issue
What you can do:
If dishes are not drying or water is not heating, professional service is recommended.
E15 – Leak Detected
This error appears when water is detected in the base of the dishwasher.
Why it happens:
- Internal leak
- Loose hose or connection
- Excess detergent or overfilling
What you can do:
- Turn off the dishwasher
- Shut off the water supply
If E15 appears, professional inspection is required to locate and fix the leak.
E16 / E17 – Water Intake Error
These codes indicate restricted or improper water flow into the dishwasher.
Why it happens:
- Kinked or damaged inlet hose
- Water pressure issue
What you can do:
- Straighten the inlet hose
- Make sure the water supply valve is fully open
E18 – Water Flow or Low Water Level Error
This error appears when the dishwasher detects insufficient water flow.
Why it happens:
- Low water pressure
- Blocked inlet filter
- Inlet valve issue
What you can do:
- Ensure water pressure is adequate
- Check and clean the inlet hose filter
E22 – Filter Blockage
E22 means there is standing water in the sump due to a clogged filter.
Why it happens:
- Food debris blocking the filter
What you can do:
- Remove and clean the dishwasher filter with warm water
- Reinstall the filter properly
E23 – Drain Pump Error
This error indicates a problem with the drain pump.
Why it happens:
- Blocked pump
- Faulty drain pump
What you can do:
- Check for visible blockages in the filter area
If the error continues, the pump may need professional replacement.
E24 / E25 – Drainage Error
These error codes mean the dishwasher cannot drain water properly.
Why it happens:
- Blocked drain hose
- Jammed pump impeller
- Improper drain hose installation
What you can do:
- Check the drain hose for kinks or blockages
- Clean the filter thoroughly
Persistent drainage issues require professional repair.
How to Reset a Bosch Dishwasher
To reset most Bosch dishwashers:
- Turn the dishwasher off
- Unplug it or switch off the circuit breaker
- Wait 5 minutes
- Restore power
- Start a new wash cycle
If the same error code returns, the issue is not temporary.
When to Call a Professional Dishwasher Technician
You should contact a technician if:
- Error codes keep returning after reset
- The dishwasher is leaking water
- It won’t drain, fill, or heat properly
- The unit stops mid-cycle repeatedly
Ignoring Bosch dishwasher error codes can lead to water damage or electrical issues.
Bosch Dishwasher Repair – Contact Alpha Tech Appliance
Bosch dishwasher error codes help identify problems, but an accurate diagnosis often requires professional tools and experience. If your dishwasher keeps showing error codes or isn’t working properly, expert service is the safest option.
Alpha Tech Appliance provides reliable Bosch dishwasher repair and installation in Toronto and the surrounding areas. Our experienced technicians handle drainage problems, heating errors, sensor failures, leaks, and control board issues safely and efficiently.
Contact Alpha Tech Appliance today to book your Bosch dishwasher repair or installation service.