Bosch Side-by-side refrigerator Error Code E21: Meaning & How to Fix It

By the ErrorCodePro Editorial Team · Last reviewed October 20, 2026

Bosch side-by-side refrigerator error code E21 means: Communication error between display control module and the ice and water dispenser control module. [1] Keep using it? Only if the owner checks below clear the code; if it returns, stop and book a repair. Start with the owner checks below, beginning with: write down the code and model number.

Source: Bosch side-by-side refrigerator error-code chart, via Sears PartsDirect [1].

Quick facts

Code	E21
Also shown as	None listed by the manufacturer
Brand / appliance	Bosch side-by-side refrigerator
System	Dispenser
Meaning (service chart)	Communication error between display control module and the ice and water dispenser control module. [1]
Keep using it?	Only if the owner checks below clear the code; if it returns, stop and book a repair
DIY-safe?	Owner checks only (listed below)
Support	Bosch Customer Support: 1-800-944-2904
Source document	Bosch side-by-side refrigerator error-code chart (via Sears PartsDirect)

On this page: Meaning · Steps · Parts · When to call a technician · Related codes · FAQ

What error code E21 means on a Bosch side-by-side refrigerator

Communication error between display control module and the ice and water dispenser control module. [1]

This is a dispenser code. Codes and wording can vary by model, so check your owner's manual for your model number.

How to fix Bosch side-by-side refrigerator error code E21 (safe owner checks)

Safety first: disconnect power before you remove any panel or reach into the sump or drum. Do not touch wiring, the control board or the motor. If you see water near electrical parts, stop and call a technician. These steps are based on the Bosch side-by-side refrigerator error-code chart (via Sears PartsDirect) [1], rewritten for clarity.

Write down the code and model number. Note exactly what the display shows (E21) and copy the full model number from the rating label, so you can confirm this chart applies to your side-by-side refrigerator and order the right parts.
Check the cookware. Check the display control module and ice and water dispenser control module for burnt spots on the circuit boards or visible damage.
Do a power reset. Unplug the appliance or switch off its breaker for one minute, then restore power and try again. If the code clears and stays away, it may have been a one-off fault.
Test and decide. Run a short cycle or restart and watch the display. If E21 comes back after these checks, stop using the refrigerator for this function and call a technician, because the remaining causes need meters or part replacement.

The first and last steps (and the power reset) are general owner checks added by ErrorCodePro; the rest follow the Bosch side-by-side refrigerator error-code chart published by Sears PartsDirect, rewritten for safe owner use.

Parts that may be involved

Exact parts depend on your model number. This page lists part types only, never part numbers.

Display control module
Ice and water dispenser control module
Wire harness

When to call a technician

Unplug the refrigerator and reconnect any loose connections on the wire harness on the display control module and the ice and water dispenser control module.
Technician: replace the wire harness if damaged.
Technician: replace the display control module or ice and water dispenser control module if damaged.
Anything involving wiring, the control board, the motor or the water valve electrics
The appliance is under warranty: contact Bosch Customer Support: 1-800-944-2904 first

Frequently asked questions

What does error code E21 mean on a Bosch side-by-side refrigerator?

The Bosch side-by-side refrigerator error-code chart lists E21 as follows: Communication error between display control module and the ice and water dispenser control module.

Is it safe to keep using the side-by-side refrigerator with E21?

Only if the owner checks below clear the code; if it returns, stop and book a repair.

Can I fix Bosch side-by-side refrigerator error E21 myself?

Only with the owner checks on this page, starting with: write down the code and model number. If it persists, call a technician or Bosch Customer Support: 1-800-944-2904.

Sources

Sears PartsDirect: Bosch side-by-side refrigerator error-code chart (third-party copy of manufacturer service data)

Last reviewed: October 20, 2026. ErrorCodePro is not affiliated with Bosch.