Why Is My Dishwasher Making Loud Noises?

Dishwashers these days are quieter than they’ve ever been. Still, hearing the sound of splashing water and mild vibrations is entirely normal. It’s only when you hear loud and unusual noises should you troubleshoot the appliance for problems.

Loud noises from your dishwasher could result from the appliance not being level or having too many items inside. Besides that, worn-out bearings or damaged impellers in its circulation and drain pumps could also cause several loud noises. Lastly, a faulty water inlet valve could also generate unusually loud shuddering and clicking noises.

In this guide, you’ll dive deep into the most likely causes behind those loud noises coming from your dishwasher. First, you’ll discover what each affected part does. Then you’ll see why they make loud noises and how you can fix them.

Why Is My Dishwasher Noisy?

When troubleshooting the loud noises coming from your dishwasher, always start with the possibilities you can rule out the quickest. 

Start with checking that your dishwasher is level and loaded correctly. Then, inspect the bearings and impellers in its pumps before checking the water inlet valve last.

In this section, let’s dive deeper into each of those possible reasons.

#1 Dishwasher That’s Not Level

Type of noises: buzzing, vibrating, knocking

Start the troubleshooting process by checking that your dishwasher is perfectly level. Being level is crucial because it ensures that water can flow correctly in the appliance. Its components can also work correctly when the machine is level.

For instance, a dishwasher that isn’t level will likely touch surrounding surfaces, especially if you have built-in cabinets surrounding the appliance. When that happens, the vibrations from the dishwasher will travel through the cupboards and make them sound much louder than usual.

You can check your dishwasher using a spirit level. These days, many smartphone apps also do the same job of a spirit level by using the device’s onboard sensors.

Suppose you need to make your dishwasher level. You can do so by adjusting its legs underneath. Manufacturers typically put 2-4 adjustable legs that you can raise or lower by turning with a wrench or similar tool.

Read: Why Are My Dishwasher Buttons Not Working?

#2 Overloaded Or Incorrectly Loaded Dishwasher Racks

Type of noise: continuous knocking

Next, check that you’re not overloading your dishwasher’s racks. When the dishwasher is overloaded, the spinning wash arms will knock any item that’s blocking their path. That will cause a loud knocking noise to come from your appliance.

Your dishwasher relies on several spray arms that spin around to wash stains off of your kitchenware. There are 2-3 spray arms, and you can find them at the bottom, middle, and top of the dishwasher compartment.

When loading your dishwasher, always make sure that there are no objects in the path of those spinning wash arms. You can make sure by turning those arms manually and testing them before starting your wash program.

Alternatively, you can also refer to the user manual for your dishwasher model. The manufacturer puts information to guide you on loading your dishwasher correctly.

Read: How To Clean A Dishwasher Rinse Aid Dispenser

#3 Worn-Out Circulation Pump Bearings

Type of noise: grinding, squealing, squeaking

After you finish ruling out #1 and #2, it’s time to move on to checking for faulty components. Of course, the first components you’ll want to inspect are the pumps. More specifically, you’re searching for noises coming from the dishwasher’s centrifugal pumps.

Dishwashers have two pumps:

• Circulation pump: Dishwashers spray and recycle water to maximize efficiency. The circulation pump makes that possible by taking water from inside the dishwasher compartment and driving it through the appliance’s spray arms.
• Drain pump: The dishwasher must remove dirty water inside the compartment to replace it with clean water. That will happen several times throughout a dishwashing program, especially at the end. The drain pump makes this possible by driving water out of the appliance through the drain hose.

Both of these pumps rely on bearings that ensure the pump impellers can spin smoothly, even at extremely high speeds. The bearings consist of rolling elements such as rollers or balls, reducing friction and allowing the impellers to spin.

Unfortunately, those bearings will wear out after being in use for many years. When that happens, the rolling elements will fail to move freely, causing the loud noises that you hear coming from the pump.

When this happens, you have two options. You can either replace the worn-out bearings or replace the pump as a whole. Your dishwasher brand and model will determine which option is more affordable and straightforward for you.

Read: How Do I Know If Dishwasher Drain Pump Is Bad?

#4 Damaged Pump Impellers

Type of noise: grinding, squealing, knocking

Besides bearings, your dishwasher pumps also rely on impellers. These are spinning components that drive water through the pump, whether that’s to circulate clean water or drain dirty water.

These impellers can also suffer damage in the form of breakages and deformities. For instance, a solid foreign object could get past the filters and inside the pump. That object could break parts of the impeller as it bounces inside the circulation or the drain pump.

Much like the bearings, you can try to replace the impellers in your pumps. However, that will depend entirely on the brand and model of the dishwasher.

In some cases, you can purchase individual spare parts for the pump, like a new impeller. Still, you might find yourself with only the option of buying a new pump entirely.

Read: Are Dishwashers More Efficient And By How Much?

#5 Faulty Water Inlet Valve

Type of noise: shuddering, clicking

Last but not least, check for a faulty water inlet valve. 

This valve is the point where your household water supply connects to the dishwasher. When the dishwasher needs clean water to flow in, it’ll signal the water inlet valve to open. Once there’s enough water, the valve will shut and prevent any overflowing.

The water inlet valve has moving mechanical parts that open and close as needed. However, it’s controlled electrically by signals from the dishwasher’s main control valve.

That means the water inlet valve can suffer electrical and mechanical faults that affect its ability to open and close.

When that happens, you’ll hear a shuddering or clicking noise from the outside. Those noises occur because the valve fails to control water flow correctly.

Unfortunately, you cannot repair a water inlet valve. The only straightforward solution is to remove the one in your dishwasher and replace it with a new valve. You can do that yourself by purchasing the spare part or by calling a qualified technician to do it for you.

Read: Should You Use Dishwasher Detergent Substitute’s?

Frequently Asked Questions (FAQs)

Here are answers to some other frequently asked questions that you’ll find helpful as you troubleshoot your noisy dishwasher.

What Makes A Dishwasher Loud?

A dishwasher can be loud if the appliance is not level or has an overloaded compartment. Besides that, worn-out bearings or impellers inside the dishwasher’s pumps are also likely mechanical causes for this problem. If those are fine, check the water inlet valve for issues as well.

Why Is My Dishwasher Making A Knocking Noise?

A knocking noise inside a dishwasher means that the spray arms are hitting something as they spin. First, open the dishwasher and ensure that none of your kitchenware is in the way of those spray arms. You can confirm it by turning the spray arms manually to see if they hit anything.

What Happens If A Dishwasher Is Unlevel?

An unlevel dishwasher can cause a series of problems for the appliance. For instance, the machine could touch surrounding surfaces and make its normal vibrations sound a lot louder than usual. Plus, your kitchenware inside will get in the way of the spinning spray arms, causing loud and repetitive knocking noises.

What Does Resetting A Dishwasher Do?

Resetting your dishwasher will clear some faults from its components. For example, that might stop noise from the water inlet valve if the root cause is an electrical or electronic fault. However, it will not fix other loud noises coming from your dishwasher.

Can You Add Soundproofing To A Dishwasher?

Yes, you can soundproof your dishwasher by wrapping a soundproof matting around the appliance. However, it’s important to remember that most newer dishwashers are already very quiet, as long as they’re well-maintained. So, before investing in soundproofing, make sure that the appliance and its parts are in excellent working order.