What are the symptoms of error code Er:21?

Washer stops mid-cycle with Er:21, Excessive suds visible in the drum, Rinse cycles repeat multiple times, Clothes feel soapy after washing

What causes error code Er:21?

Using too much detergent, Using non-HE detergent, Soft water increasing suds formation, Detergent residue buildup in the drum

How do I fix error code Er:21?

Run a rinse/spin cycle to clear excess foam., Use HE detergent and reduce dosage., Run a hot empty cycle to remove residue., Check for detergent buildup in the drawer.

Bosch Washer - Er:21 Error Code

The washer detected excessive foam during the cycle.

Meaning

The washer detected excessive foam during the cycle.

The Bosch Er:21 error code indicates that the washer detected excessive foam levels inside the drum. Legacy Bosch washers use foam detection logic based on motor load, water level fluctuations, and drain behavior. When too much detergent or non-HE detergent is used, foam builds up and prevents proper rinsing, triggering Er:21. The washer may extend rinse cycles or stop entirely to prevent oversudsing damage.

Symptoms

Washer stops mid-cycle with Er:21
Excessive suds visible in the drum
Rinse cycles repeat multiple times
Clothes feel soapy after washing

Causes

Using too much detergent
Using non-HE detergent
Soft water increasing suds formation
Detergent residue buildup in the drum

🔧

Step-by-Step Fixes

Run a rinse/spin cycle to clear excess foam.
Use HE detergent and reduce dosage.
Run a hot empty cycle to remove residue.
Check for detergent buildup in the drawer.

⚠️

Safety Notes

Avoid opening the door mid-cycle when foam levels are high.

📋

Applicable Models

Show Models

WFL2060
WFR2460
WFMC2100

📁

Bosch Washer Er:22 – The washer aborted the spin cycle due to imbalance or safety conditions.

📁

Other Bosch Washer Error Codes

Show All Error Codes

Model-Specific Notes

On WFR models, Er:21 often appears when using powdered detergents in soft water regions.

Disclaimer

The information provided on this page is for educational and informational purposes only. Repairs involve electrical, mechanical, and water-related risks. Always follow manufacturer instructions and consider contacting a qualified technician for diagnosis or repair.