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Bosch Dishwasher Noise Problem

Bosch dishwashers are known for being quiet dishwashers so it can be concerning when it starts making noise. How do you know if the noise is normal or if it is a sign something is wrong?

A common reason for a Bosch dishwasher to make unusual noises is a clogged spray arm. Food particles and debris can get lodged in the spray arm, causing it to become obstructed. To fix this, turn off and unplug the dishwasher, then remove and clean the spray arms. Ensure all holes are free from debris, then reattach the spray arms and restart the dishwasher.

Another potential cause of noise in a Bosch dishwasher could be a misaligned dish rack. If dishes are not loaded properly, or if the rack is off its track, it can create rattling or banging sounds during operation. The solution is to adjust the dish rack, ensuring it’s properly aligned and securely in place. Also, rearrange dishes so they are stable and not likely to move around during the wash cycle.

Modern dishwasher in the kitchen

Some noise coming from the dishwasher is normal but if the noise is exceptionally disruptive, the issue requires some investigation. Before you give up on your dishwasher, this article will help you troubleshoot the issue.

Bosch Dishwasher Noise When Draining/Loud Drain Pump

Tired man sitting on the floor behind the dishwasher

Is your Bosch dishwasher making loud noises as it drains? The reason why is not complicated.

If your Bosch dishwasher makes noise when draining/loud drain pump, the drain pump may be defective or something is stuck in the sump assembly. The pump will make a grinding or scraping sound if there is food stuck in the pump.

Two main reasons why the dishwasher is making noises when draining are a clogged line or a clogged drain pump.

Clogged Line

We take for granted that we can load our dishwasher with dishes that still have food on them. The food has to go somewhere, though. If food is not broken down and it becomes stuck, the dishwasher will make loud noises as it tried to drain.

The dishwasher will make a gurgling sound if water is not able to drain out due to a clog. The first place to investigate the issue is the drain hose. Make sure the hose connected to the disposal is not kinked or pinched.

Drain Pump

The second place to troubleshoot this issue is the drain pump. The drain pump removes the dirty dishwater from the dishwasher as clean water is coming in for another cleaning cycle.

If the drain pump becomes clogged with food or other debris, the pump will struggle to work and will make a squealing noise as it tries to drain water out of the dishwasher.

The pump can easily be removed and inspected. Be sure to wear protective gloves when checking the pump though. There could be glass shards that have fallen into the pump.

Bosch Dishwasher Noise When Washing

Modern dishwasher in the kitchen

Normally a Bosch dishwasher is very quiet as it works. What does it mean when you start hearing noises as it washes?

Generally speaking, if your Bosch dishwasher makes noise when washing, the noise is due to the wash cycles changing. Another possibility is if the dishwasher is not fully loaded or is loaded incorrectly, the items will move around or will obstruct the spray arm from making a full rotation.

There are other common noises that can be heard when the dishwasher is running.

Knocking or Rattling

The spray arm is critical to ensuring water reaches every dish in the dishwasher. It needs to be able to rotate freely.

If the spray arm is not able to spin freely, you will hear knocking or rattling sounds as the arm hits dishes inside the dishwasher. Thankfully, this sound can easily be resolved by rearranging the dishes so the spray arm is not obstructed.

When loading the dishwasher, be sure to leave enough space between items so water can reach everything. Leaving a little space between items will also prevent the dishes from rattling against each other, which could cause them to chip or be broken.

Here are some good tips to keep in mind when loading your dishwasher:

  • Tall glasses such as wine glasses should go on the bottom rack in the secure glass holder.
  • Larger items such as plates and cutting boards need to go on the side. Placing them on the side will prevent them from obstructing the spray arms and blocking water flow.

If the banging sound is not rhythmic, this means there is something wrong with the water pressure and you are hearing the water pipes rattle. You will need to call a plumber to diagnose the water pressure issue.


These sounds are heard when the dishwasher timer and electronic controls are in use. You may also hear these sounds when the dishwasher changes wash cycles.


The dishwasher fills and drains several times throughout the washing and rinsing process. Every time the water is drained out, the solenoid will make a snapping sound.

Another reason why you hear a snapping sound could be the dish detergent dispenser. It opens quickly to dispense the detergent so you could be hearing it snap open.


Thumping sounds are common when the drain hose is loose and is bumping against the back of the dishwasher. Adjusting the drain hose will require pulling the dishwasher out to inspect the line.

Pulling the dishwasher out will also allow you to inspect the hose, making sure it is not pinched or has debris sitting in it.

Bosch Dishwasher Noisy Startup

Woman putting plates in the dishwasher

Dishwashers make our life so much easier but when they start making noise it can be stressful. Here is the reason why the dishwasher is noisy on startup.

If your Bosch dishwasher is noisy on startup, this could be the dishwasher’s normal startup sounds. If the noise is particularly loud, the drain pump could be blocked or there is food in the food disposal blade.

Typically, Bosch dishwashers, in general, are very quiet. But there are a lot of moving parts to the dishwasher so it is not uncommon to hear some noise as these components start working.

Two common sources of startup noise are the wash impeller and the water inlet valve.

Wash Impeller

The wash impeller is the plastic propeller arm that forces water throughout the dishwasher. If one of the blades is broken, bent, or warped, the blade will scrape against the pump housing and make noise.

Copyright protected content owner: and was initially posted on March 31, 2022.

Water Inlet Valve

The water inlet valve lets water into the dishwasher. Typically the inlet valve is silent and you only know the valve works because the dishwasher gets your dishes clean.

Over time, as the dishwasher is continually used, the diaphragm inside the inlet valve will start to break down. As water is forced through the valve during the filling cycle, it will interact with the defective diaphragm inside the valve, creating a loud buzzing or even high-pitched squeal sound.

Bosch Dishwasher Whistling/Buzzing/Humming

Modern dishwasher in the kitchen

Do you feel like your dishwasher is serenading you with the whistling, buzzing, and humming? These are the sounds of a dishwasher busy at work.

If your Bosch dishwasher is whistling/buzzing/humming, these sounds are normal operational sounds and are nothing to worry about. You are hearing the fan’s rotation as it cools the main pump; the drain pump is working; the food disposal is grinding food and pushing it out of the dishwasher.

The most common reason for a buzzing sound is the food disposal grinding food. The more food particles there are, especially if there are larger, the louder the buzzing sound will be. This sound is normal and is a sign the disposal is working.

Bosch Dishwasher Loud Water Noise

Man fixing the dishwasher

Dishwashers use a lot of water to wash and clean our dishes. While we expect to hear some water noise, what does it mean when the water noises are loud?

If your Bosch dishwasher is making loud water noises, you are hearing the drain pump forcing water down the drain. The loud water noise could also mean there is a blockage in the drain and the water is not able to drain out.

It is normal to hear some noise when the drain is working, however, if the noise is particularly loud or bothersome, you can remove the drain yourself to inspect it.

The following steps will walk you through the process. You will need protective gloves and a teaspoon.

Step 1: Remove the bottom dish rack.

Step 2: Remove the spray arm and then lift the filter out.

Step 3: Use a towel or sponge to soak up any standing water in the bottom of the dishwasher.

Step 4: Put on your protective gloves and then use the teaspoon to gently lift the pump cover off.

Step 5: When the cover is loose, pull it upwards until you feel some resistance and then pull it towards you, completely removing it.

Step 6: Very carefully, reach into the pump to remove any foreign objects. Be careful of any broken glass shards!

Step 7: Once you have cleaned the pump, replace the cover, making sure it clicks into place.

Step 8: Before returning the filter, inspect it for any food or other debris.

Step 9: Place the filter back in the dishwasher, making sure the arrows line up.

Step 10: Put the spray arm and dish rack back inside the dishwasher and run a test cycle to see if the noise has stopped.

Bosch Dishwasher Loud Motor Noise

Modern dishwasher in the kitchen

Is your Bosch dishwasher motor making loud noises as it runs? The pump motor could be the issue. As the motor becomes worn down with use or if it has a buildup of hard water inside it, the motor will become increasingly louder.

If your Bosch dishwasher makes loud motor noise, there could be a buildup of calcium and other minerals from the hard water. The buildup weighs down the pump impeller, throwing it off balance and causing it to be noisy as it operates.

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Copyright article owner is for this article. This post was first published on March 31, 2022.

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