Many dishwashers come with promises of being quiet during operation, and this may be true. However, some noise comes with the territory, especially when there are components like the motor and water in use while the dishwasher is running. The sound that comes when water fills in during the cycle is usually a sloshing or filling noise and this is typically normal.
Water Fill Cycle
When water enters the dishwasher, it comes through the fill valve and makes a hissing or flowing sound. It then sounds like sloshing when the spray arms begin to move the water around in the unit. These noises are both normal and should be low in volume and temporary in duration.
Water should enter the dishwasher freely, but if the dishwasher makes a loud noise and does not seem to fill with water as expected, the water supply may be turned off. The water valve is usually found under the kitchen counter or behind the dishwasher and should be turned counterclockwise to open. Straighten out the water hose as well to make sure there are no bends in the hose that might prevent the water from moving into the unit.
Water Inlet Valve
The water inlet valve on a dishwasher can eventually begin to fail due to use or damage. When this occurs, the dishwasher may make loud noises when the water fills the dishwasher, including rattling, shaking or vibrating. This is an indication that the water inlet valve needs to be replaced. While this is something some homeowners can do, it is typically something worth contacting a service repair center for assistance.
Another possible source of noise when the dishwasher is filling with water is the pump, as debris or food can get caught in the pump and cause noise. To check this out, disconnect power to the dishwasher and take out the bottom spray arm. Inside the spray arm is a fan called the impeller that might be blocked or damaged. Clean away any debris or contact a service center for assistance if it seems to be broken.