It takes a while for this to drain. Am I getting an air or vapor lock condition due to the "S" shape used with this trap. I did this due to the shelf in the vanity.


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    The s shape should not create an air lock, in fact it would have the opposite affect of creating a vacuum that would pull the water out of the trap and leave it dry thereby allowing sewer gas to enter the home. ( which i why they are not allowed. ) It sounds like a vent issue, a plugged vent or no vent. The vent is there to allow the drain to function properly, without it there can be an air lock situation. – Alaska Man Jul 7 '19 at 23:47
  • @AlaskaMan indeed. The only other thing to note is this run could be clogged.But still need to fix as noted. – noybman Jul 8 '19 at 4:48
  • @noybman Thanks. I disassembled the trap and ran an entire ten foot snake that would easily reach the 3.5 inch stack this feeds into and the snake came out clean. Where it enters the wall, there's a 90 degree elbow and about a 4' run of 1 1/2" that feeds into the stack, which is the only vent in this arrangement. – Raybo Jul 8 '19 at 13:33
  • So how did you ensure the vent is not clogged? – JPhi1618 Jul 8 '19 at 14:56
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    4' before it is vented, it is possible that this could be the problem area. Do you not have a sanitary tee in the wall with a vent going up and a drain going down ? – Alaska Man Jul 8 '19 at 17:16

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