Air pressure in sink drain pipe prevents drainage

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JG plumbing

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Since you like to tell people to look definitions up.......please learn the difference between allude and elude.

You’ve done this several times. There’s a difference you know. 😘

Bills not running from anyone is he 🤡

Maybe the EPA ? How about The FBI for price fixing on toilet repair ? 🤡

I was really hoping the “ dishwasher vent hose “ was the problem. I wanted to be wrong once.......
You do a good enough job of making a fool of yourself no reason to point out all of the dumb things you say.
 

PerplexedPlumber

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Hello - I am an American living in Sweden and am trying to fix an issue under our sink where the drain water can not drain unless I pull out the light gray flexible tubing inserted into the dark gray piece (pictures below) to allow some air vent, otherwise the air pressure in the pipe does not allow any drainage at all.

The upper piece is only inserted into the bottom piece, it is not fastened. The thinner flexible piece on the right is the dishwater drain tube.

When a large volume of water is dumped into the sink, like when emptying a bucket for example, the system seems to get overwhelmed and the water cannot drain fast enough, the upper pipe gets forced deeper into the lower pipe closing off the air, then water overflows out of gap an runs all over. The force of a lot of water creates a back pressure that the pipes cannot vent.

It has been happening more often now, with less quantities of water to trigger it.And now happens when the dishwasher is run. The water still drains fine when just the tap is running. If I forced the two pipes together, then there is no drainage at all.

I snaked the line today as far as I could, about 40 feet, and forced through some sludge, but it didn't seem like any major blockage.

The two pipes are not connect fast, but only one inserted into the other. I have been using a workaround where the top pipe is not inserted fully into the bottom piece to allow some venting. But that is now failing.

It is a fairly new kitchen install (within the past 5years) and I asked a local plumber when it first happened if perhaps there is a venting issue, but he said it was not venting, snaked it real good, but said that was about all he could do.

In summary, if I push the two pipes together, there is no air venting and no drainage. As a workaround, I pull the tubes apart slightly to allow some venting which enables drainage. But this can lead to leakage, and the system gets overwhelmed when, for example, I pour a bucket of water in the sink or fill then empty the basin, and water leaks out an onto the floor.

Drainage in our shower and all other sinks in the house are fine. So I am thinking there is something wrong with the set up versus an issue with the main sewage line running out of the house.
Looking for some advice......Thanks!
View attachment 30715
The P trap isn't level, as another poster indicated. Have you checked the solids trap that is part of that P trap? Also, as another poster indicated, what looks like a dishwasher drain should be in a high loop - easily amended by securing it along the top of the wall. If that drain pipe goes straight down into the floor and there is no vent for that line, that would be another issue, also as another poster indicated. If this is a wood floor, you should be able to check. If it is concrete, you may be left with an air admittance valve as the best venting solution.
 

Twowaxhack

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The P trap isn't level, as another poster indicated. Have you checked the solids trap that is part of that P trap? Also, as another poster indicated, what looks like a dishwasher drain should be in a high loop - easily amended by securing it along the top of the wall. If that drain pipe goes straight down into the floor and there is no vent for that line, that would be another issue, also as another poster indicated. If this is a wood floor, you should be able to check. If it is concrete, you may be left with an air admittance valve as the best venting solution.
The problem is solved, the drain was clogged up. The OP had a pro clean the drain.
 

JG plumbing

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The problem is solved, the drain was clogged up. The OP had a pro clean the drain.
I would be shocked if you ever played organized sports at any kind of notable level. The weakness in your character doesn't support that experience.
 

PerplexedPlumber

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The problem is solved, the drain was clogged up. The OP had a pro clean the drain.
It may be resolved only temporarily. No mention of vent being resolved. If solids trap isn't level and isn't cleaned out periodically, issues may persist. Personally, I don't like chronic problems.
 

Twowaxhack

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It may be resolved only temporarily. No mention of vent being resolved. If solids trap isn't level and isn't cleaned out periodically, issues may persist. Personally, I don't like chronic problems.

That’s how they pipe things in Sweden. It’s common there.
 
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Iceman 64

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It may be resolved only temporarily. No mention of vent being resolved. If solids trap isn't level and isn't cleaned out periodically, issues may persist. Personally, I don't like chronic problems.
I got some good tips from all the ideas posted here. Thank you. The immediate problem was solved by a pro drain cleaner who busted out the clog down at the cellar-level. Seems like the venting issue is solved too. I asked the drain guy about the venting issue and he explained why I was experiencing it (I understood his point, I think, I am not 100% fluent in Swedish) I looped the dishwasher hose up high so it is no longer coiled up on the ground. It was not the source of the problem, but probably something that should have been done regardless. In retrospect, it seemed like the DW never drained properly.

I did clean out the solid trap and the piping just below the sink before I had the pro drain cleaner here; there was some residue, but not enough to solve the problem. I'll make sure to clean it our periodically. Perhaps all these things together contributed to the bigger problem and needed addressed. I dont want to have to do this again in 5 years.

Sweden has some different-looking P-traps, and set-ups in general. Water and the laws of physics are same everywhere, but the equipment just a little different....
 

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