No draining but no blockage???

[goteante]

Hello,

My sink doesn't drain, but when I separate the siphon from the pipe and pour water directly into the pipe, there is no problem. Same with the siphon itself. I don't see a blockage anywhere, but when I put it all together, there it is!

Maybe it is something to do with physics?

Picture of the set up attached.

Any help would be really appreciated.

Many thanks!

 

[frodo]

have you looked from the siphon up?

maybe the problem is before the siphon

 

[goteante]

Hello frodo, thanks for your reply.

Yes, I'm afraid I've done that and there is no problem there either.
Everything works fine, separately, and there are no visible residues blocking anything.
That and the fact that the problem arises when I connect the siphon to the pipe makes me think that it is something to do with something I cannot see in the pipe. Although I cannot explain why there is no problem with it if I use it without the siphon! That's why I can only suspect some physics I don't understand related to the shape of the siphon, stagnant water somewhere down the pipe creating some weird effect or I truly don't know what. It is very hard for me to imagine the reason and how to fix it.

 

[frodo]

sounds like your straw has a finger on it, lol

here is a simple physics lesson,

glass of water, put a straw in it. plug the end of the straw with your finger
pick the straw up
liquid stays in the straw
remove finger. water exits the straw

where are you located ? from the piping it looks like Italy ?

 

[goteante]

Spain.

I'm not completely unfamiliar with air pressure, that's why I dropped that about the siphon and something down the drain, but I don't have the knowledge to resolve my problem. If anyone is familiar with Torricelli's Law, Bernoulli's principle or any other great law of physics and can provide a possible explanation and/or solution...
I'm very ignorant when it comes to that =)

If only I could see the finger on the straw, instead of having to be sitting here with the other proverbial finger up somewhere else!

 

[alefromitaly]

try to open the siphon..if without siphon the water runs correctly and with the siphon you have the problem,probably this last needs to clean..inside the bottle siphon there is the vertical pipe that create the siphon..try to check if this is long the necessary..if this is too long can create problems..

 

[alefromitaly]

A tip..there are types of siphon called "salvaspazio" made by lyra..I know that they export also in spain..these siphon have a best conformation than the bottle siphon..

 

[goteante]

Hello alefromitaly, thanks for your reply.

The siphon is clean, there is nothing blocking the water passing through, that is why I'm lost as to why it doesn't work when connected to the rest of the elements, and why I can only think of the pipe as a culprit, even when I don't know the cause.

About the length, you can see it in the picture, what do you think?
Out of curiosity, how does that part being too long affect the functioning, exactly? Also, It's been working without a problem for 15 months at least (when I started to live here), wouldn't the length have an effect from the beginning?

Thanks for the tip about the Lyra siphons, I will check them out =)

 

[Zanne]

I've never seen this in US plumbing. What is that for?
I have no idea how it is supposed to work and I am curious.

 

[goteante]

I've never seen this in US plumbing. What is that for?
I have no idea how it is supposed to work and I am curious.

It basically keeps any residues at the bottom of the siphon, I reckon. It might be called barrel trap in US, and I heard they are obsolete. No moving parts.

See EXTREMELY crude diagram.

 

[alefromitaly]

depends..in this case,you have these possibilities..first:unscrew the inspection end make s control,(so you can see if the vertical pipe is too long)..the second:change the siphon with another more efficent(the price of siphons for the kitchen are not high)..if the problem persists,probably there is a clogging or a ventilation problem on the main line..but at now,I doubt..a question..is the water completely stop,or the water drains slow?ps good luck for the soccer match of this morning

 

[alefromitaly]

Sorry..evening..

 

[goteante]

Thanks for the reply.

I have used a toothbrush to clean the pipe and the siphon as good as I can, even though there were no visible obstructions, and the water flows slightly better, but I can't leave it running for long or it overflows. So, it doesn't stop, but drains slowly.

I don't understand the part about the pipe being too long. What length is too long? If it was too long, wouldn't that affect it from the beginning, instead of starting to have problems now?

If the siphon works fine on its own, there is no problem with it, or could it be anyway?

When you say ventilation problem, what do you refer to? As far as I know, plumbing here doesn't have vents, unlike U.S. (or Italy??).

Thanks again for all the suggestions and explanations.

 

[alefromitaly]

in EU there are only one main ventilation (are few the cases when you find two or more ventilations like in the usa)..did you unscrewed the inspection?at the end of the drainage you hear a noise like "glu glu?"have you a stopper with a basket or completely closed?

 

[goteante]

I did check, but I still don't understand what you mean by the pipe being too long, so I don't know what to look for.

You nailed that "glu glu" noise at the end. What does that indicate?

This is my stopper:

 

[alefromitaly]

sometimes,depend by the model of the siphon,the vertical pipe can slide inside the bottle for do siphon..if this pipe is too long,can create problems with little dirt..now,I dont know the brand of your siphon,so I'm not sure that this is the real problem..it is a supposition..if you hear noise like "glu glu",there are two supposition..the first is that miss the ventilation (or is too far from the sink)..the second,is that the main drain pipe is almost clogged..(junk of kitchen,oil,low quality of the soap of the dishwasher,incorrect slope of the pipe)..if you are realli sure that your siphon is installed in correct way,and is clean in every parts,the problem moves in the main drain pipe..(I hope for you no)..mi tips are:change the siphon with another less obsolete with full drain like lyra,geberit,viega etcc..with one of this you should noticed less foam durin the drain of dishwasher.(inexpensive solution)if the problem persists,call a good plumber with idro snake and inspection camera for do a videoinspection (expensive solution)..third;if you do not have the ventilation,or if is too long,exists a kit called "glu-glu stop" always made from lyra,that you can install with the new siphon..in this way,you increase the velociti of the drain water and you give the right rapport "air-water",necessary for a correct drain..most important thing,the stopper like your,must not be removed during the drain..never..

 

[Zanne]

Oh! So by "too long" you mean that the pipe might be protruding too far into the siphon? If it is pushed in too far, could it be obstructing the opening of the siphon?

I wonder what the glu glu stop is called in Spain. I know here it is called an Air Admittance Valve (AAV).

 

[frodo]

the straw and the glass I spoke of earlier, is what happens when the vent is blocked.

the thumb over the straw [vent], represents a bolckage, the straw [vent pipe] will not drain because the atmosphere pressure on both sides is not equal.

when the thumb [blockage] is removed the pressure is equal . the straw [pipe] will drain.

i tnink from what ALE described, the tube in the syphon trap is blocked or is in to far.

i would like to have one of those things in my hand to investigate

 

[Caduceus]

sometimes,depend by the model of the siphon,the vertical pipe can slide inside the bottle for do siphon..if this pipe is too long,can create problems with little dirt..now,I dont know the brand of your siphon,so I'm not sure that this is the real problem..it is a supposition..if you hear noise like "glu glu",there are two supposition..the first is that miss the ventilation (or is too far from the sink)..the second,is that the main drain pipe is almost clogged..(junk of kitchen,oil,low quality of the soap of the dishwasher,incorrect slope of the pipe)..if you are realli sure that your siphon is installed in correct way,and is clean in every parts,the problem moves in the main drain pipe..(I hope for you no)..mi tips are:change the siphon with another less obsolete with full drain like lyra,geberit,viega etcc..with one of this you should noticed less foam durin the drain of dishwasher.(inexpensive solution)if the problem persists,call a good plumber with idro snake and inspection camera for do a videoinspection (expensive solution)..third;if you do not have the ventilation,or if is too long,exists a kit called "glu-glu stop" always made from lyra,that you can install with the new siphon..in this way,you increase the velociti of the drain water and you give the right rapport "air-water",necessary for a correct drain..most important thing,the stopper like your,must not be removed during the drain..never..

Is this what you are describing as a possibility, Al?

 

[Zanne]

Is this what you are describing as a possibility, Al?

I think that even if the pipe only partially covered the side opening it would cause problems because it would still restrict the full flow-- causing unequal pressure.