Bosch Dishwasher Error Code E4

E4 means the control board cannot position the water switch. The water switch directs water flow through different parts of the wash system, and when the board commands it to move and gets no confirmation, it stops the cycle and displays E4. The fault can come from the switch itself, its wiring, or debris blocking its movement.

No, you should not continue running cycles with E4 active. The dishwasher has stopped specifically because water cannot be directed correctly, and forcing cycles could result in flooding, no water reaching the dishes, or damage to the pump and heating element. Leave the machine off until the fault is resolved.

Yes, replacing the water switch is a repair many homeowners can handle. You will need to remove the lower spray arm, filter assembly, and likely the sump cover to access the switch. Have your model number ready before ordering a replacement part to ensure compatibility. If you are uncomfortable working around the electrical connectors or disassembling the sump area, a qualified appliance technician is the right call.

Start by resetting the dishwasher: turn it off at the power switch or unplug it for two minutes, then restart. If E4 returns, inspect the area around the water switch for debris or blockages and clear anything you find. Next, check the wiring harness connected to the switch for loose connectors or visible damage. If the wiring looks intact and the switch is still not moving, the switch assembly will need to be replaced.

If the cause is a debris blockage or a loose wire connector, the repair costs nothing beyond your time. Replacing the water switch assembly typically runs between $30 and $80 for the part, plus one to two hours of labor if you hire a technician, bringing the total to roughly $100 to $200 depending on your area. A control board replacement is more expensive, often $150 to $300 for the part alone, so confirm the board is actually faulty before ordering one.