Five Reasons Your Dishwasher is Making Noise

Grinding, droning, buzzing, and whistling sounds are commonly heard in the kitchen provided someone is grinding coffee beans, using an electric can opener, or heating up water in a tea kettle. But if those noises are coming from your dishwasher, you’ve got more than an annoyance; any of those sounds could indicate a problem with the appliance. Why is the dishwasher making such a nuisance of itself? Read on.

Why is my dishwasher making a grinding noise?

All the top manufacturers, such as Bosch, GE, Whirlpool, Frigidaire, Kenmore, LG, and Samsung, like to promote how quiet their dishwashers are when going through the fill, wash, or drain cycles. Expectedly, the more higher-end models have better insulation, so they tend to run more quietly. Still, it’s a good idea to understand what kind of sounds to expect when the dishwasher is running properly, so you’ll be more attuned to that abnormal sound that could indicate a part failure.

Following a short drain cycle to remove any water that may have been left in the dishwasher’s sump, the selected wash cycle begins when the control sends 120 volts of alternating current to the water inlet valve solenoid which opens the valve and allows the proper amount of water into the tub. This process will take anywhere from 90 seconds to two minutes and will usually allow around two gallons of water to fill the tub. As expected during this cycle, you should hear the sound of water pouring into the tub… and nothing else. If the sound of water is accompanied by a loud buzzing, squealing, or whistling, the water inlet valve could be wearing out.

Once the fill cycle has completed, the control sends voltage to the circulation pump motor which uses an impeller to force water through the dishwasher’s wash arms. During this cycle, you may hear the slight hum of the circulation pump motor as well as the sound of water splashing against the dishware. A grinding or droning noise heard during a wash or rinse cycle could indicate the bearings in the circulation pump motor have failed or are in the process of failing. A scraping sound could indicate the pump’s impeller has become dislodged or has a broken fin.

After the completion of each wash cycle, the control sends voltage to the drain pump that uses an impeller to force the water through a drain hose to a garbage disposer or standpipe. During this drain cycle, you will hear a sucking sound as the water is pushed through the drain hose accompanied by the low hum of the drain pump motor. A grinding or droning sound will, again, indicate a problem with the bearings in the motor, while a scraping sound could indicate the impeller is damaged or dislodged. Some models without a separate drain pump will use a drain valve solenoid to open and close a flap to drain water through the drain hose or retain the water in the sump. A defective drain valve solenoid can get stuck in the open or closed position and will often emit a buzzing sound when failing.

Top 5 dishwasher parts responsible for noisy operation

So, there’s not much mystery behind the reasons your dishwasher is making such a racket. Each noise is usually associated with a specific part that is malfunctioning in some way. Here are the most likely culprits, and they can all be replaced with a minimum of fuss by a patient DIYer:

  1. Defective drain pump – In addition to the drain pump motor bearings wearing out, the pump itself can become clogged with food debris. You can try cleaning any debris from the pump to see if that improves performance, but you may need to replace the component with a new one.
  2. Malfunctioning circulation pump – As with the drain pump, the circulation pump motor bearings will simply wear out over time, resulting in a grinding or droning sound during wash or rinse cycles. Since the bearings cannot be replaced individually, you will need to install a new circulation pump to solve the problem.
  3. Worn water inlet valve – The diaphragm inside the inlet valve can deteriorate and deform after years of use. When this happens, the water passing through the valve can produce a loud buzzing, squealing, or whistling sound. Since worn inlet valves cannot be easily or successfully repaired, we recommend replacing the valve altogether.
  4. Damaged impeller – Both the circulation pump and drain pump use an impeller to propel the water through the wash arms and drain hose, respectively. If the impeller has become dislodged or has a broken fin, you may hear a scraping or squeaking sound during a wash or drain cycle. Depending on your dishwasher model, you may be able to replace a damaged impeller independently of the pump.
  5. Defective drain valve solenoid – A buzzing drain valve solenoid is a strong indicator that the part has failed. Drain valve solenoid kits are available that will allow you to replace the solenoid itself, as well as components like the plunger, actuator lever, and spring.

Keeping your dishwasher quiet with the right parts with Repair Clinic

If you’ve determined you need to replace a dishwasher pump, impeller, drain solenoid, or water inlet valve, how can you find the right part for your particular dishwasher? Repair Clinic makes it easy. To get started, you’ll need to identify the dishwasher’s model number which can be found on a label attached to the top or side of the dishwasher door. Enter the full model number of the appliance in the Repair Clinic website search bar to see a full list of compatible appliance parts. You can then use the “Part Category” filter (“Pump”, “Valve & Float”) along with the “Part Title” filter (“Drain Pump”, “Circulation Pump”, “Water Inlet Valve”) to narrow that list down to identify the specific part that fits your model.

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