Bosch Dishwasher Error Code Er:20

Er:20 means the dishwasher terminated the spin cycle because either the communication link between the main control board and the inverter board was lost, or an unbalance condition was detected. The control board shuts down the cycle as a protective measure when it cannot confirm the motor is operating correctly. The first step is to check the dish load for uneven weight distribution, then inspect the wire harness connecting the two boards.

A reset may temporarily clear the error code, but if the underlying cause is a communication failure in the wiring or a faulty inverter board, the code will return when the cycle reaches the spin phase again. A reset is worth trying after you have redistributed the dish load. If the error reappears after a reset, further electrical diagnosis is needed.

If the issue is simply an uneven load or a loose harness connector, the repair costs nothing beyond your time. Harness repairs or connector replacements typically fall in the range of $50 to $150 in parts and labor. If the inverter board needs replacement, parts and labor costs generally range from $150 to $350 depending on the model and service rates in your area. A main control board replacement is typically at the higher end of that range or above.

Start by rearranging the dishes so the load is evenly distributed, then restart the cycle to see if the error clears. If it returns, inspect the wire harness and all connectors between the main control board and the inverter board for loose connections, corrosion, or damaged wiring. If the harness is intact, the inverter board or main control board may need to be replaced by a technician.

The dishwasher is designed to stop the cycle when Er:20 occurs, which means it is protecting itself from operating with an unconfirmed motor condition. Running repeated cycles while the error persists is not recommended, as continued operation with a communication fault could put additional stress on the motor and control components. Addressing the cause before regular use is the safer approach.