Error Code: E21 Difficulty: Hard
Problem: Communication error between the display control module and the ice and water dispenser control module.
How to Fix E21 Error (Step-by-Step)
- Unplug the refrigerator from the wall outlet to ensure your safety.
- Attempt a system reset by leaving the refrigerator unplugged for 10-15 minutes to allow the internal electronics to discharge, then plug it back in. If the error persists, proceed to the next step.
- Access the display control module, which is typically located behind the main user interface on the exterior of the refrigerator door. This may require carefully prying off a plastic cover or removing a few screws.
- Locate the ice and water dispenser control module, usually found inside the dispenser housing itself. You will likely need to remove the dispenser drip tray and front panel to access it.
- Carefully inspect the wiring harness that connects the display module to the dispenser module. Look for any pinched, frayed, or disconnected wires. Securely reconnect any loose plugs you find.
- If the wiring appears intact, one of the control modules has likely failed. It is recommended to replace the dispenser control module first. Disconnect the wire connectors from the old module, remove it from its mounting, and install the new one in its place.
- Turn the appliance off, wait about 2 minutes, then turn it back on.
Recommended Parts to Check
No exact official OEM part number is listed here because the correct Bosch refrigerator part can vary by complete model number. These are targeted part-category searches, not universal fit claims.
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Bosch refrigerator temperature sensorCommon replacement category: Temperature sensor / thermistorFit note: Exact OEM part number varies by full Bosch refrigerator model number. Confirm compatibility before buying.Confidence: Medium
This category can be relevant for temperature, alarm, and cooling-sensor faults after the door seal, vents, and settings are checked. -
Bosch refrigerator evaporator fan motorCommon replacement category: Evaporator fan motorFit note: Exact OEM part number varies by full Bosch refrigerator model number. Confirm compatibility before buying.Confidence: Medium
This category can be relevant for airflow, fan, and uneven-cooling symptoms after ice buildup and obstructions are ruled out. -
Bosch refrigerator electronic control boardCommon replacement category: Main electronic control boardFit note: Exact OEM part number varies by full Bosch refrigerator model number. Confirm compatibility before buying.Confidence: Medium
This category can be relevant for repeated electronic, display, or cooling-control faults after connectors and power are checked.Search Amazon for Bosch refrigerator electronic control board
Before ordering: match the part to the complete Bosch refrigerator model number on the appliance tag.
Still Not Working?
If the replacement part didn’t fix the issue, you may have a wiring problem or main board failure.
More options (for a better recommendation)
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When It’s Better to Replace Than Repair
Refrigerator repairs can become costly when sealed-system, control, defrost, fan, or ice-maker issues repeat.
Confirm width, height, depth, door swing, counter-depth needs, water line, and delivery path before ordering.
For repair parts, verify exact fit with the full refrigerator model number before buying; these links are general replacement-appliance shopping options.
- [OK]Water inlet valve, ice maker, or fan failures keep returning
- [OK]Defrost heater, thermostat, or sensor faults stack up
- [OK]Compressor or sealed-system repair is not economical
- [OK]Food-loss risk is becoming a pattern
Recommended Refrigerator Replacement Options
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Expert: Mike Sullivan
EPA Section 608 Certified Technician with 18+ years experience.
Read Editorial Standards →Browse all Bosch error codes: Bosch Error Codes
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