Noisy kitchen sink during dishwasher pumping out

[reljicb]

Hi all!

Could someone please help me understand what went wrong so that my sink has become unbearably noisy during dishwasher pumps water out. The water is going down pipes and makes a loud noise.

I have replaced an old dishwasher with the new one some time ago. I don't know if it is coincidence, or not. I don't even remember if it became noisy right after the replacement.

Please have a look at the attached photo for details about plumbing.

Thanks in advance for ideas.

 

[Newboy]

The dishwasher connection is above the trap level so you will hear the water being pumped into the pipework which is open to both sink wastes.

You dishwasher waste connection is wrong and maybe leading to the sump in the d/w filling with waste water.

The d/w waste pipe needs to rise to the height of the underside of the worktop before it connects to the sink waste pipework - an inverted 'U'

 

[reljicb]

Thank you @Newboy!

I'll try to fix the dishwasher waste as you suggested to prevent potential d/w filling with waste water.

What should I do about the d/w connection above the trap? Should it be below the trap? Can that have some disadvantages?

 

[Newboy]

The connection point is OK but do raise the pipework - you don't want the dishwasher sump to end up full of cr*ppy sink water.

 

[reljicb]

So, if I understand well, I cannot do anything to reduce the noise?

 

[JohnD]

You could reconfigure the plumbing with a trap immediately under each sink plughole, and a standpipe with trap for the dishwasher.

 

[Madrab]

So, if I understand well, I cannot do anything to reduce the noise?

Not with an above trap spigot no. The noise travels up the pipe and then the sink amplifies it, like the body of a guitar.

There are other waste manufacturers that may have a better design and smooth the water flow as it enters the waste and may reduce the noise a little but without knowing how loud yours is it's impossible to say.

The only way I have managed to reduce the noise to its minimum it to use an appliance standpipe and then use a McAlpine twin spigot appliance adapter (V33WM).