Dishwasher Clanking Noise

Water Inlet Valve

• The water inlet valve on your dishwasher can indirectly cause clanking and rattling. The valve may eventually wear out, and it may not open or close as quickly as it should to start and stop the flow of water to the appliance. When this happens, it can cause the water to struggle as it flows into the dishwasher. This can cause a noise similar to hydraulic shock or “water hammer” that will clank pipes together in some instances and can certainly vibrate your dishwasher violently, causing dishes to rattle together.

Detergent Cup

• About halfway through your dishwasher's washing cycle, you may notice an audible clank or clunking noise from inside the dishwasher. This is a normal sound produced by the detergent cup. The spring-loaded lid to the cup where you put your detergent in the dishwasher flies open at the appropriate time during the wash cycle. When it does, the lid slams against the door of the dishwasher, resulting in the noise you hear. There is no reason to be concerned about this noise.

Spray Arm

• Inside the dishwasher is a spray arm that spins and shoots water onto the dishes to get them clean. The spray arm is designed to rotate freely without colliding with anything. But sometimes a large dish or pan gets in the way, causing the spray arm to bump it as it spins throughout the cycle. This can create the clanking noise. You can open some dishwashers during the wash and rearrange the load, or you can simply deal with the noise until the cycle is finished. It is unlikely that the spray arm will be damaged in the process. If you have fragile glassware in the load, you should make sure it is not in the way of the spray arm to avoid breakage.

Water Pressure

• Dishwashers need considerable water pressure to get the dishes clean, but sometimes lightweight dishes move around when the stream of water from the sprayers hits them. This can cause the dishes to bump together and cause the clanking sound that concerns you. Very fragile pieces could be broken by this contact, but usually this is not a major worry.