When your dishwasher makes a noise when it starts up and stops suddenly, it's typically due to the normal operation of its internal components and water flow. Here are some common reasons for these noises:
Water Inlet Valve: When the dishwasher starts, it fills with water. The noise you hear at the beginning is likely the sound of the water inlet valve opening to allow water into the dishwasher's tub. This is a normal part of the dishwasher's operation.
Water Pump: The noise during startup and shutdown might also be caused by the water pump engaging and disengaging. The pump is responsible for circulating water throughout the dishwasher during the wash cycle and draining the water at the end of the cycle.
Spray Arms: During the wash cycle, the dishwasher uses spray arms to distribute water and detergent across the dishes. The sound of water spraying from the spray arms can be heard during startup and while the dishwasher is running.
Drain Valve: At the end of the wash cycle, the dishwasher needs to drain the water from the tub. The noise you hear when the dishwasher stops suddenly could be the drain valve closing to prevent water from flowing back into the tub after draining.
Electronic Control Board: The dishwasher's electronic control board manages the various functions and cycles. It can make a noise during startup as it initializes and controls the dishwasher's operations.
Dish Movement: As the dishwasher fills with water and the spray arms start rotating, dishes and utensils may shift slightly, causing minor clinking noises.
If the noises are sudden or excessively loud, it's worth checking for any foreign objects or debris that might be obstructing the dishwasher's components, such as the spray arms or pump. In some cases, dishes or utensils may be improperly loaded, causing them to rattle or interfere with the dishwasher's parts.
However, keep in mind that some noise during dishwasher operation is entirely normal and shouldn't be a cause for concern, as long as it's not accompanied by any other performance issues or error messages. If you notice unusual sounds persisting or if you suspect a problem with your dishwasher, it's best to refer to the manufacturer's user manual or contact a qualified technician to inspect and diagnose any potential issues.