Kitchen Sink Drainage Confusion

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I have pointed out 2 things under the sink that are wrong. i do not care a frack how long the sink has been draining fine,
theses 2 things are wrong. Plus,a 3rd issue, the hose from the dishwasher is not installed correctly

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I have had a dishwasher all my life without problem. Im now living in an apartment in Theale (near Reading) and bought a dishwasher. At first everything was OK for around a year then around a month ago my sink stopped draining. Initially I thought it was a blockage and someone came out but there was no blockage. On experimenting I have discovered it is related to the dishwasher because when i unscrew the dishwasher 'Tap' and let the resultant sink water run out into a pot it drains fine. But reconnect the dishwasher, boom no sink draining. So i am confused. Is there an air issue, pressure issue or feedback issue? Or do i need a different kind of sink trap. theres only space in my kitchen for one undercounter item, If it had been a washing machine i wonder if i would have same issues.

I am not a plumber and have no expertise, just a girl desperate to have everything working again. I have attached a photo of my undersink setup. and if anyone can explain to me what the problem is or a local plumber reads this and knows a different kind of trap and can come out and fix the problem I will pay him.


I need a couple of questions answered and will not reply if these are not answered
1] when yo disconnected the dishwasher hose, and drained tested the sink, did you plug the dishwasher hose inlet and the water drained into the sewer or did the water drain into the pot via the dishwasher hose connection hole in the p trap?
2]what is the brand and model dishwasher
3] are you able to replace the trap piping configuration yourself? or hire it out?
 
What is the source of that second hose, located higher up on the drain tailpiece?

Meanwhile, it seemed like the OP stated that the sink drained just fine, when draining directly from the open dishwasher connection into a pot or bucket.
Which of course it would.

If that is what was stated, then that would not give any info about a possible clog somewhere farther down into the drain line.

And plumbers can be talented, or can be incompetent, and low bidders often get the first crack when hired by associations.

EDIT I was writing same time as previous poster.
 
I have pointed out 2 things under the sink that are wrong. i do not care a frack how long the sink has been draining fine,
theses 2 things are wrong. Plus,a 3rd issue, the hose from the dishwasher is not installed correctly

View attachment 28067

I need a couple of questions answered and will not reply if these are not answered
1] when yo disconnected the dishwasher hose, and drained tested the sink, did you plug the dishwasher hose inlet and the water drained into the sewer or did the water drain into the pot via the dishwasher hose connection hole in the p trap?
2]what is the brand and model dishwasher
3] are you able to replace the trap piping configuration yourself? or hire it out?


Oh finally someone actually offers some advice that can be practically applied.

1) Yes the sink drained into the sewer at normal speed, hence why i know there are no blockages further reinforced by two plumber visits who used both hoover and wire snake to check for blockages when i thought that was the issue.
2) Dishwasher is a Slimline Electra C1745B/S?W
3) I imagine it will be easy to replace the undersink piping which is as already said basically a screw on lego set if i know all the right lego set to construct and can source the right parts, i think it would be easy. In fact i would prefer a different set up because the u bend is way too low in the undersink cupboard and makes it difficult to use that area for storage, so moving the u bend elsewhere would be great.

Let me just add that this is the setup my landlord provided, theres around 60 apartments in this block, you can be sure its all the same in each one. Most people are using washing machines i imagine, i elected for a dishwasher myself.
 
The thing is that S traps are illegal because they cause a siphon that breaks the trap seal.

The problem here as explained is that the kitchen sink will not drain with the dishwasher hose connected.,

The dishwasher can be disconnected and capped and the sink then drains fine.

That’s the information that’s been given.,
 
That thing the man has his hand on is called an auto vent
I have no idea what the fittings and pipes are calld in your country
so show this picture to a guy that knows in your area.

We use a wye branch tail piece here you use that tee to hook up the dishwasher

that hose MUST loop up to the bottom counter top. and be tied off then loop back down
 
Adding that air admittance valve will not change anything unless the trap is siphoning.

Toilets are S traps and they flush fine.

If I set up a kitchen sink with an STrap , filled it up with water and then pulled the plug......

You’re telling me it won’t drain without a auto “ vent “ ?
Lol 😂

Care to place a wager ?
 
i just want to check something Twowaxhack said 'S' traps are illegal, its definitely an 'S' trap under my sink right?

I googled and apparently 'S' traps are not plumbing code here either. I want the facts before I broadside my landlord with 20 40 pounders...
 
i just want to check something Twowaxhack said 'S' traps are illegal, its definitely an 'S' trap under my sink right?

I googled and apparently 'S' traps are not plumbing code here either. I want the facts before I broadside my landlord with 20 40 pounders...
I’ve already checked your code. They’re not legal.
But it’s also not your problem either.,s traps will drain fine., That’s not why they’re illegal.

Plenty of things work that are not code.
 
yes what im trying to establish is can i go on the offensive against my landlord? or is it accepted to use these things here...I couldnt find out from google.

Its certainly interesting for you guys looking at my project as its UK, and NOT USA, probably fascinating to get into it..

Fracked if i know anything about Plumbing, this wasd as it was when i moved in except i bought a dishwasher and a plumber plumbed it in. And i gurantee every flat will have same set up.
 
Wouldn't a dishwasher air gap supply air, similar to an AAV, allowing this the sink to drain properly?
 
Wouldn't a dishwasher air gap supply air, similar to an AAV, allowing this the sink to drain properly?
Sinks drain fine without dishwashers.

Toilets flush fine with S traps.

it makes zero sense why capping the dishwasher connection allows the sink to drain normally. I’d have to see it to believe it.
 
Sinks drain fine without dishwashers.

Toilets flush fine with S traps.

it makes zero sense why capping the dishwasher connection allows the sink to drain normally. I’d have to see it to believe it.

yes i know i dont understand either...As i said i had zero problems until around 6 weeks ago, which is why the label thing doesnt make any difference.

the only thing the last plumber said was something about if the pipes had shifted that would cause feedback or something along those lines, whatever that means..
 
What is going on in my opinion
the s trap is causing a back syphon
the no loop condition is causing a a back syphon in the opposite direction
these two are working against each other and causing an air lock at the trap

Pick up the hose, tie it to the bottom of the counter
get rid of the strap and toss an a aav


sinks will drain all day long with an s trap. they will stink but will drain


take a straw and put it in a glass of water. put your finger over the end of the straw and lift it out of the water
did it drain? nope. no vent
remove your finger, it drains it has a vent
 
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