Miele Washer Error Code F4123

F4123 indicates a backup comparison fault between two internal control modules, the ELP 235 and the EW 235. The washer's control system performs periodic checks to confirm that both modules hold matching backup data, and this code appears when that comparison cannot be completed. It is an electronic control-level fault and is not related to mechanical components like the motor or pump.

A power reset can sometimes clear F4123 if the fault was triggered by a one-time event such as a brief power interruption during a module sync cycle. To reset, disconnect the washer from power for several minutes, then reconnect and run a test cycle. If the code reappears, the underlying hardware or communication issue must be diagnosed and repaired before the fault will stay cleared.

Repair costs for F4123 vary depending on the root cause. If only a wiring or connector issue is found, labor costs alone may range from $100 to $200. If one or both of the ELP 235 or EW 235 control modules need to be replaced, parts and labor combined can range from $300 to $600 or more, depending on parts availability and local labor rates. Getting a diagnostic assessment from a Miele-authorized technician is the best way to estimate costs accurately.

Some cases of F4123 are caused by transient power interruptions that leave one module with incomplete data, and a controlled power reset may clear the fault without further repair. However, if the code returns after resetting, the cause is likely a hardware or wiring issue involving the ELP 235 or EW 235 modules, which requires opening the machine and working with internal electronics. This level of diagnosis is best handled by a qualified appliance technician.

F4123 is a control integrity fault, meaning the machine has flagged a problem with its own internal data verification system. It is not advisable to continue using the washer while this code is active, as the control system may not be operating with fully verified parameters. Continued use without resolving the fault could lead to additional errors or unpredictable machine behavior.