Kitchen Sink Drainage Confusion

[PeterW]

Hi,

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.

Thanks,

Kate & Peter

 

[havasu]

Make sure the plug is removed where the dishwasher line connects to the plumbing. Many are sealed until a dishwasher hose is connected to it, so you would have to pop out the plug.

 

[SHEPLMBR]

You may have a blockage further down the line and between the volume and the velocity of the water coming out of the dishwasher is showing the clog more quickly. Where the sink is not draining as fast and just seeps past the clog.

 

[PeterW]

@havasu: sorry if I appear thick but in the picture the dishwasher is currently connected as you can see. The dishwasher works fine and when used fills up the sink so im not sure what you mean about the plug? I would imagine based on what ive said its already removed, but if you describe in more detail i can check. The fact that the dishwasher drains into the sink tells me theres no plug to remove right?

@SHEPLMBR: The sink is not draining at all. I have had 2 guys here. First one fixed a hoover to the pipe and sucked stuff out, that didnt solve it, second one did same thing but also brought the wire device to push down the pipes, and that didnt solve it either. So how could it be a blockage unless outside the building? Also as I said when dishwasher cap is disconnected and a normal cap put back on sink drains fine.

So it has to be something to do with the fact a dishwasher is connected to the plumbing right?

 

[havasu]

@havasu: The fact that the dishwasher drains into the sink tells me theres no plug to remove right?[

Yes, you are correct. Just covering all the bases.

 

[SHEPLMBR]

@havasu: sorry if I appear thick but in the picture the dishwasher is currently connected as you can see. The dishwasher works fine and when used fills up the sink so im not sure what you mean about the plug? I would imagine based on what ive said its already removed, but if you describe in more detail i can check. The fact that the dishwasher drains into the sink tells me theres no plug to remove right?

@SHEPLMBR: The sink is not draining at all. I have had 2 guys here. First one fixed a hoover to the pipe and sucked stuff out, that didnt solve it, second one did same thing but also brought the wire device to push down the pipes, and that didnt solve it either. So how could it be a blockage unless outside the building? Also as I said when dishwasher cap is disconnected and a normal cap put back on sink drains fine.

So it has to be something to do with the fact a dishwasher is connected to the plumbing right?

I missed the "draining in pot" part. My apologies.

 

[PeterW]

the sink drains fine, but only when the dishwasher is removed and a normal cap put back on, so it has something to do with the junction on the trap...right? the junction that leads to the dishwasher. Is it something to do with air? is there a better undersink trap I could buy for connecting additional things. As i say ive had dishwashers before but have never had this issue.

and help me understand the physics here. So the water in the ubend with an empty sink is up to the edge of the junction that leads to the connected diswasher pipe. the dishwasher when used empties water down the pipe which when reaching the plumbing fills up my sink. if the sink drained in its own time that would be fine, but its not, the water is just sitting there. Now with a full sink that would mean the whole pipe is filled including the junction pipe to the dishwasher and up in to the sink.

There are no blockages as two plumbers have been here, and as said above sink drains fine without the dishwasher connected.

So why wont the sink drain when dishwasher connected. It makes no sense to me. Or is it related to water pressure because the water pressure in this flat is not the best. All the flats here have their own boilers which are on the same level as the taps almost and water pressure has never been very good., and if its water pressure why did it work for a year without issue?

 

[havasu]

Incoming water pressure should have no bearing on your dishwasher draining. 99% of our members and experts here live in the USA, so we may have a learning curve with "flats" in the UK.

 

[phoenixmac]

... 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....

Hi Kate & Peter and others - I'm not a plumber and with deference to the folks that really know what they're talking about, I'm a little confused.

Question 1:
K/P - you said two plumbers came and said there were no blockages. Is that no blockages in the dishwasher drain hose or no blockages in the P-trap/drain?

In your original post you stated that the sink really only empties into the pot, not down the drain. Is that correct? ( I assume any plumber would snake the drain or check for a blockage between the sink and the wall, but what if the blockage is downstream from there where the pipe from the kitchen meets the main?

Question 2:
What is it with two connections from the tailpiece to the dishwasher? (Not seen that before but hey, there's a lot I've not seen)...
The label on the lower hose says to install it (inlet hose?) above the top of the trap outlet. Doesn't the riser coming out of the p-trap effectively raise the outlet of the trap above the hose? My understanding of the instructions are that the hose would need to be above the blue line. Is that right?

Maybe I'm just off in the weeds with entirely too much time being stuck at home during the pandemic but I can't make sense of it, let alone why any of this would keep the sink from draining normally (unless there's a blockage somewhere further down the drain pipe).

thanks ....

 

[PeterW]

i appreciate your effort to reply but wont address most of it as much of what you have said is a repsonse to misreading my original post/not reading it correctly.

However in regards the label bit I would say ordinarily it might be a good point, except I did clearly say in my original post that i had no problems with the dishwasher for a whole year connected the same way and only last 6 weeks or so has something funny been going on. if your point was valid it would have been applicable from day one not suddenly a year or 18 months later. And in UK plumbing the dishwasher if connected where it is supposed to be, either a dishwasher or washing machine can go here and that is what the junction if for.

Thanks for taking time to think about it though. Its most frustrating. Im normally smart enough to solve most problems whatever they are but I just dont understand what the issue is here.

 

[Twowaxhack]

According to the label your piping is not correct.

If the sink will not drain then you have a blockage at some point in the piping if it has been working in the past.

It’s that simple. Be more persistent and find the trouble or hire a professional with experience.

I’ve never left a job and told the customer “ I give up, I can’t help you “

We solve the problem if the customer is willing to pay. End of story.

 

[PeterW]

as @havasu earlier said: ...Incoming water pressure should have no bearing on your dishwasher draining. 99% of our members and experts here live in the USA, so we may have a learning curve with "flats" in the UK...

So i understand that few here will understand UK systems. From 12 months experience with this dishwasher connected set up and as i have already posted i can say that this @Twowaxhack ..According to the label your piping is not correct.. doesnt mean anything regardless of what label says. If the set up worked for 12 months problem free it would still work. That isnt the problem. But if you think this is the issue then suggest to me a more appropriate trap system/setup i can buy instead of the current one on my picture and i can always try it and buy the parts. Sinks are basically a lego set anyway..

@Twowaxhack ... If the sink will not drain then you have a blockage at some point in the piping if it has been working in the past... As i have already said, the sink drains fine, when the dishwasher is not connected, so i think it has something to do with an air pocket or feedback being created when the machine is connected.

@Twowaxhack... It’s that simple. Be more persistent and find the trouble or hire a professional with experience... As already posted ive had two professionals here, both sent by my landlords in house care team. The pipe snake thing has been used and also a hoover on the pipe. if there was a blockage it would have to be in the pipe outside my property and outside my control as the sink is against outside wall, the second professional said something about the pipes moving out of alignment maybe and causing some kind of feedback but ive yet to have someone from the landlord confirm if this is the case.

 

[havasu]

Mentioning "landlord" says it all. You touch that and break it, you bought it. Seems to me your landlord is flaking on his responsibilities to provide minimal living conditions.
In America, once it has been documented well, renters have the right to get it corrected, and subtract it from the rent.
Across the pond, I don't know what legal issues you would have.

 

[PeterW]

actually my landlord is pretty good for a Housing Association. Like anything theres way too much nonsense bureaucracy in my opinion but trust me from long experience they are pretty good landlords. that said obviously when they own lots of apartments they will buy the cheapest products and materials etc.. No living condtions are pretty good, they are pretty good apartments except the boiler is crap and water pressure is not the best.

And they have sent two plumbers so far without fuss, its just more difficult for them with Covid and restrictions, plus im not even sure what the issue is. And believe me they already know im capable of making a big fuss publicly, so they dont mess around, if i need help they get on it because the alternative for them is bad press and media coverage, due to my personal power. Crap they dont want.

I think they are just not sure what to do next/plus Covid..

 

[Twowaxhack]

The part about them not knowing what to do next tells me you need someone more experienced. Covid is here too and that has no affect on me knowing what to do.

If my sink didn’t drain when the dishwasher was connected.......and someone pointed out that according to the directions clearly on the hose it was improperly connected......

I’d correct the problem. Then continue to diagnose if that didn’t correct it.

Maybe something else has changed in the system that now it matters how that hose is connected.

Correct what you know is wrong is the proper way to proceed.

 

[PeterW]

yer i get it so ill tell you what, why dont you provide the right information about the correct parts i need to rebuild the undersink plumbing which is basically a lego set and ill buy the right parts and rebuild it with your advice. im not a plumber but i am of superior intellect having graduated from Oxford. im sure i can manage it. And last i checked and despite what an earlier guy said about 99% of members here are american [though i didnt see this saying American plumbers Forum!] i highly doubt water flows down american pipes any different than it flows down UK pipes, in fact insuspect most of the kit will be entirely similar or same.

Could you manage that?

Because so far like most forums, ive noticed folks say a lot here, but dont actually say anything thats concrete or useful beyond a cacophany of opinion.

 

[Twowaxhack]

yer i get it so ill tell you what, why dont you provide the right information about the correct parts i need to rebuild the undersink plumbing which is basically a lego set and ill buy the right parts and rebuild it with your advice. im not a plumber but i am of superior intellect having graduated from Oxford. im sure i can manage it. And last i checked and despite what an earlier guy said about 99% of members here are american [though i didnt see this saying American plumbers Forum!] i highly doubt water flows down american pipes any different than it flows down UK pipes, in fact insuspect most of the kit will be entirely similar or same.

Could you manage that?

Because so far like most forums, ive noticed folks say a lot here, but dont actually say anything thats concrete or useful beyond a cacophany of opinion.

Start by following the directions clearly printed on the hose. If you can’t do that then hire a plumber who can.

Once that’s done, check to see if that solved the problem. If not then you’ll need to do further diagnostic work.

That’s the correct information. No one promises to solve your problem here but only provide a path.

I’ve provided that path.

 

[PeterW]

really? tell me how do i follow the directions printed on the hose with the current parts under my sink never modified by myself and provided as standard by my landlord? perhaps you miseed my first post that had a picture attached, or you missed the bit in the message about...

@Twowaxhack...yer i get it so ill tell you what, why dont you provide the right information about the correct parts i need to rebuild the undersink plumbing which is basically a lego set and ill buy the right parts and rebuild it with your advice...

._.

 

[Twowaxhack]

really? tell me how do i follow the directions printed on the hose with the current parts under my sink never modified by myself and provided as standard by my landlord? perhaps you miseed my first post that had a picture attached, or you missed the bit in the message about...

@Twowaxhack...yer i get it so ill tell you what, why dont you provide the right information about the correct parts i need to rebuild the undersink plumbing which is basically a lego set and ill buy the right parts and rebuild it with your advice...

._.

Your plumbing is completely different than the plumbing in America for that drain.

I suggest you calling your landlord back and informing him that you still have a drain problem.

And that the plumbing is incorrectly installed according to the directions printed on the hose.

 

[PeterW]

i already have contacted landlord so yes, im sure something will happen when theres less problems with Covid.

In meantime my learning curve has begun where i try and figure out how to rebuild the undersink lego set so that the dishwasher pipe connects somewhere else. i dont think its that complicated tbh, just requires different parts, different kind of trap and so on.. its hard to be confident when not a plumber but as i said its basically a lego set so...

different trap, different pipe bits with more options and so on..looks like im going to have to become an honorary plumber whether i wanted to or not LOL