Bosch Dishwasher Noisy Operation
Bosch Dishwasher Drain Pump
First, check the drain pump to ensure that it is clear of debris. If the drain pump is clean but it is still noisy, replace it.
Bosch Dishwasher Circulation Pump
The circulation pump motor has bearings that wear out over time. When the motor bearings fail, they generate a continuous drone. If the motor bearings have failed, you must replace the entire circulation pump.
Bosch Dishwasher Drain Impeller
The drain impeller pushes water through the drain hose and into the garbage disposer or drain line. If the impeller is broken, replace it.
Bosch Dishwasher Pump and Motor Assembly
Part of the pump and motor assembly (such as the motor bearings, drain impeller, or wash impeller) might be defective. Often, you can replace the pump’s individual parts. However, if you do not want to disassemble the pump to replace its parts, or if the parts are not available separately, you can replace the entire pump and motor assembly.
Bosch Dishwasher Wash Impeller
The wash impeller is a small plastic blade that forces water through the spray arms. If one or more of the impeller blades is broken, the dishwasher will make noise. In addition, if the impeller is damaged, warped, or bent, it can scape against the pump housing. Inspect the wash impeller for damage. If the wash impeller is damaged, replace it. On most models, you can replace the wash impeller independently of the pump and motor assembly. Search for your model number to determine if your impeller is replaceable. If the impeller cannot be replaced separately, you will have to replace the entire pump and motor assembly.
Bosch Dishwasher Circulation and Drain Pump Motor
The circulation pump motor has bearings that wear out over time. When the motor bearings fail, they generate a continuous drone. If the motor bearings have failed, replace the motor or replace the entire pump and motor assembly.
Obstructed wash arm
There are several wash arms in a dishwasher, typically one for each rack. If a handle or untensil is sticking through one of the racks the wash arm may be hitting it as it turns. Or there may be an item that is too tall and obstructing the upper wash arm. Confirm that nothing is obstructing the upper or lower wash arms.
Bosch Dishwasher Water Inlet Valve
The water inlet valve opens to allow water to enter the dishwasher. When it is new, the water inlet valve is very quiet during operation. Over time, the diaphragm inside the valve deteriorates and deforms. This deformation interacts with the water rushing in and can produce a loud vibration, buzzing, squealing, or other noises. If the dishwasher is loud during the filling cycle, replacing the water inlet valve may solve the problem.
Bosch Dishwasher Circulation Pump Motor
If the noise is happening only during the wash cycle, it’s quite likely a worn out circulation pump motor is the cause. The circulation pump motor has an impeller and bearings that can wear out over time. When the motor bearings fail, they generate a continuous drone. If the impeller is broken or damaged, it will produce a grinding noise. If either the bearings or impeller are damaged, you must replace the entire circulation pump.