I’ve been having trouble with a sink drain that intermittently allows odor up. It has a standard 1.25 drain and trap, but for some reason it will smell pretty bad, only when the water is run. I remodelled about 4 years ago, installing new vanity and sink, had to use a corregated plastic pipe to line up the sink with the wall, but still used a standard trap. What would cause the trap to allow the gas up through it like that? Is there a dimensional issue that I dont know, like how far a drop from the sink to the trap should be?
As always, thanks for your replies.
Tom
Replies
This question comes up pretty regularly. Do you have well water? That's my guess. It may also be the last fixture or room on the run.
Do a search on well water. There was an extensive discussion/ thread within the past month.
F
I don't understand... what type of plastic corrugated pipe? Are you saying you used it because it would flex and otherwise you could not make the connection? Doesn't sound OK to me... it should all be solid pipe.
The drop from a fixture to the trap should be minimized. Otherwise the water dropping to the trap can cause continuous air space thru the trap. There's a code maximum for that distance, I think 24". Less is better.
Yes, that is what I used it for, the alignment of the sink and the outlet through the wall needed an adjustable piece to hook them together, So above the trap I used a corregated piece that allowed me to align things up. The trap is below the corregated piece, then goes right into the wall. Dont know if I can hook it all up without a manipulated piece.
Is 1.25 better than 1.5 on diameter? Does it make a difference if I have both spliced together?
Thanks,Tom
I don't want to insult anyone by mentioning the "obvious" but I couldn't help but think, with your description of the smell being associated with the water running, of my weekend cabin in the springtime, when high ground water somehow forces water into our well from a source that has an incredibly high sulfer content. It stinks so bad it's hard to be in the room with running water.
Andrew
This smell is definitely from the drain. I have well water, and a chlorinator but the water does not smell like this. It is a funky smell that isnt sulpher, which is identical to the smell of the drain when I had the sink out. I read the previous posts on this and found it interesting. Maybe I'll try a double trap, like someone else did, or at least make a better attempt to lose the flexible pipe.
Tom
Could it be that the corrugated drain piece is trapping alot of crud, and when the water rushed by, it allows the air from the crud back up?It could also be that the corrugations of the drain are interupting the air flow, you know, some sort of "venturi" effect or something like it, that prevents the air and water from smoothly exiting the pipe?
I think greenarch is onto something... maybe two things. Anyway, you have a non-standard installation and you should replace it with standard tailpiece and trap parts. If you have a proper trap adapter on the tee into the wall you should be able to connect everything without any corrugated pipe. Start by fixing that and see if it improves.
Thanks for your comments. I'm not sure what you mean by a "proper trap adapter on the tee into the wall". The wall has a 1.5 inch pipe coming out of it...I guess you mean the tee that one side provides venting, then the other runs the waste away...right? What is the adapter, is that just the compression attachment from the trap? The wall outlet and sink dont line up, so that is why I used the flex pipe, couldnt get it to work without it, at least at the time. I must be ignorant of certain fittings that would make it work right.
Tom
A trap adapter is a compression fitting that is installed into the horizontal leg of the drain/vent tee. One end glues into that tee, the other end has the compression fitting. It is the fitting that the trap arm connects to... your interface to the wall. It allows you to adjust the in/out position of the trap arm a little bit so that you can align everything and get it tightened up. There are similar compression fittings on the trap so that you can adjust the up/down position there, and the trap itself swivels in the middle... so you have plenty of play in the whole assembly and should be able to connect everything up without flex pipe. This is all based on the white PVC trap/tailpiece stuff that's common at Ace Hardware. All of goes together without a wrench, just tighten by hand. You need to test fit everything and carefully cut the pieces to length before assembling.
couldnt get it to work without it, at least at the time
You may have needed a better trap kit. A good trap set should allow for more than 3 dimensions of movement to get it in.
So, I suspect that the drain connection in the wall may be too high--otherwise you would have just trimmed the tail piece from the sink drain to fit.Occupational hazard of my occupation not being around (sorry Bubba)
Just read throught this forum...thought I'd offer this up, even though you may have checked this. If you've got a strainer basket in your sink drain(s), you might want to pull them out and check for the nastiest smelling stuff you would never expect to find not in your plumbing pipes. Remove the set screw and pull 'em out...you'll know immediately wether or not this is the problem. Reset the strainer basket in plumber's putty when replacing, that should keep the crud from collecting.