Bosch Dishwasher Error Code F42

F42 means the dishwasher's control board has detected that the incoming mains power frequency is outside the acceptable range of 50 Hz plus or minus 5 Hz or 60 Hz plus or minus 5 Hz. The appliance halts operation to protect its components from potentially damaging out-of-spec power. This is primarily a power supply fault rather than an internal appliance fault. A specialist should measure the actual frequency at the installation site to confirm whether the supply is the problem.

No, you should not attempt to run the dishwasher while F42 is active. The error indicates the appliance is receiving power outside its acceptable frequency range, and continuing to operate under those conditions could damage the motor, pump, or control electronics. The dishwasher's control system has intentionally stopped operation for protection. Wait until the power supply issue has been diagnosed and resolved before using the appliance again.

Repair costs vary widely depending on the root cause. If the problem is with your home's electrical supply, you may be looking at electrician service fees ranging from roughly 100 to 300 dollars or more depending on what wiring or circuit work is needed. If the dishwasher's control board is found to be faulty after the power supply is ruled out, control board replacement parts and labor can range from approximately 150 to 400 dollars. Getting a power quality assessment first is the most cost-effective starting point before committing to any parts.

In most cases, F42 requires a qualified electrician to diagnose and resolve the power supply issue rather than a DIY dishwasher repair. You can check whether other appliances on the same circuit are causing an overload and try isolating the dishwasher on its own circuit breaker. However, measuring mains frequency accurately requires proper test equipment and electrical knowledge. If the power supply is confirmed normal, a technician would then need to evaluate the control board.

A reset may temporarily clear the F42 code, but the error will return if the underlying power supply issue has not been corrected. If the fault was caused by a brief, one-time grid disturbance that has since resolved, a reset may be sufficient. However, if the mains frequency at your location is consistently outside the valid range, the error will reappear with each wash cycle. Always have the power supply checked before assuming a reset is a permanent fix.