I've noticed the same thing with mine, but it's intermittent - most of the time I still can't hear it, so I assume its something I've put in the machine, like a pot. But I don't really know - I haven't done any real investigation.

Have you changed dishwashers soaps? The type of soap can affect the viscosity of the water which would result in different sound levels. Another thing to consider is whether you have purchased new pots, pans, or dish ware.

For me, none of the above :-)

I did change dishwasher soaps - maybe I'll try one of the old soaps and see if that's it. If so, wow :) It's like a 15+ decibel difference. Will report back!

Have you tried cleaning the DW with a citric acid cleaner? We are finding that Dw's are getting calcium deposits faster than before and they can ubstruct the sensors that measure the water clarity making the DW think the water is dirtier and on a varible speed motor like the Bosch the motor will run faster and spray harder to clean the "dirtier" dishes.

double post

This post was edited by jakvis on Fri, Dec 12, 14 at 13:59

why does it matter ???

It is not a silent appliance.

Humans describing sound (particularly DWs ) is so subjective as to be fairly irrelevant. Unless you've measured with a dB meter and a spectrum analyzer to tell which frequencies have gone up or down , it is really difficult to say the unit IS louder with any degree of accuracy.

You also now have a baseline with which to compare, before you'd never heard a Bosch so your expectations were skewed.

DOn't over think things - it's a dishwaser, not an airplane or rocket.

Why does it matter?

It matters because I bought the Bosch because of it's reputation for quiet operation, and it is mostly almost silent. So when it gets louder with time, it's a legitimate question to ask to see if I can figure out why. It does matter to those of us with small spaces and or open-concept rooms.

You missed my point - you don't KNOW that it got louder because you didn't measure the sound output then and now.

You PERCEIVE that it got louder and are now disappointed because your EXPECTATIONS were : " it is mostly almost silent "

What I'm saying is it's probably just perception again !

Just enjoy your new kitchen is all I'm saying. If you need re-assurance call in for a service call. Tell em makes a clonking wooshing sound that it didn't two weeks ago.

It is not silent. or even nearly silent and Miele and Asko have the same reputation for being quiet. But they are not silent either.

And , to add fuel to the fire - no one really knows how these companies actually come up with those dB ratings they tout in the sales jargon and since there is no industry standard you shouldn't really worry about it. All you can really gleen is that a DW with a lower dB rating from the same manufacture will be quieter than the one with a higher one. DOn't assume that a 43dB rating from brand X is quieter than one with a 45 dB rating from Brand Q.

Actually, I think it makes more noise when its less full. Yes, larger load, more items muffle and deflect the spray from hitting the tub walls.

Hi I picked up this thread because I have the same issue. 1 year old Bosch dishwasher that you could not tell was on is now quite loud. There are DB apps so it is possible to tell the difference definitively. So yes there is an increase. It’s a bother as I am now working at the kitchen island. Will check the warranty and find out what can be done without any extra cost at this time.. thanks for your post. Did you ever solve the issue? Thanks!

I have noticed the same thing, which is how I ended up on this thread. I don't need some smart ass telling me that I need a DB tool to be sure. It used to be silent, now it is as loud as a typical washer. no noise to noise is easy to measure. Has anyone discovered an answer yet as to why this is happening? Used to love it when I couldn't hear it at all and had to check for the red light shining on the floor to know it was even on.

First thing to do is to run the dishwasher empty. Does it still sound louder? There is a chance it won’t.

Our Bosch dishwasher (with water softener and third rack) was also sounding louder than we remembered. It sounded like either a louder swishing noise or the propeller arms hitting something while they were spinning . However, when we ran it empty, it was just as silent as when we bought it. In our case, we discovered that the noise was due to two things: (1) the position of our middle rack and (2) how we loaded the bottom rack.

The propeller arm is attached to the bottom of middle rack. The middle rack is adjustable. The lower the middle rack, the closer the propeller arms are to the dishes below. The water comes out of this propeller with significant force, The propeller arms also have some wobble in them up and down (seems to by design because we didn’t find anything that seemed to have come loose). It appears that the pressure from the water hitting a dish in the bottom rack can push the propeller arm up while it’s spinning causing substantially louder swishing noise. The lower the middle rack position and the taller the dishes in the bottom rack, the closer the dishes are to the sprayers and the more pronounced this is. From our experiments, the noise from this alone is significant. The other issue is that when one propeller arm swings up a little the opposite one swings down a little. if dishes are too tall, the propeller can actually hit a dish as it is spinning.

Presumably, adding a third rack, causes the middle rack to be closer to the bottom rack by default than it might be in a two rack dishwasher so this problem might be more pronounced.

This might or might not be the problem that the rest of you are noticing but the simple experiment of running the dishwasher empty will quickly give you a definitive answer.

I just had my Bosch dishwasher installed. The first 2 loads, quiet. I had to look to see if the red light was on. This evening it sounds like my old klunky dishwasher I replaced this with...