Miele Washer Error Code F4255

F4255 indicates an EFU (Electronic Frequency Unit) fault caused by low input voltage. Specifically, the washer has detected that the incoming supply voltage has dropped below 320 Veff on the EFU 235 input circuit. This is typically caused by a tripped fuse, a missing phase, or a low-voltage condition in the electrical supply. The machine shuts down to protect its components until the power supply issue is corrected.

No, you should not attempt to operate the washer while F4255 is active. The error indicates the appliance is not receiving adequate voltage, and running it under these conditions could damage the motor drive, control electronics, or other internal components. Resolve the power supply issue before resuming use.

Repair costs depend on the cause. If a tripped breaker or blown fuse is the issue, costs may be minimal, typically in the range of a few dollars for fuse replacement or no cost at all for resetting a breaker. If internal wiring or the EFU module requires replacement, professional repair costs can range from around $150 to over $500 or more depending on parts and labor rates in your area.

Some causes of F4255 are DIY-accessible, such as resetting a tripped circuit breaker or replacing a blown supply fuse. However, if the problem involves internal wiring, terminal block connections, or the EFU module itself, a qualified appliance technician should perform the repair. Working with the electrical supply to a large appliance carries serious shock and fire risks if not handled correctly.

A simple reset will not permanently clear F4255 if the underlying power supply problem has not been fixed. The EFU continuously monitors incoming voltage, so the fault will return immediately or shortly after restart if the voltage remains below 320 Veff. You must identify and correct the root cause, such as restoring a tripped breaker or repairing a wiring fault, before the error will stay cleared.