Are you sure it is not plumbed this way?
We have several houses that we lease. On one of them, the tenant called and said the kitchen sink wasn't draining. Fine, used a 25 foot snake, found an obstruction at about 15-18 feet in, after several tries got it to drain properly. BUT, in the process, based on what we were seeing, we THINK that the only venting that is going on is, say you're using on side of the sink, the venting is being done from the other side of the sink. We think there might have been an obstruction between the garbage disposal and the other side, which we were able to clear out by running the garbage disposal. Possibly the vibration cleared it. In other words there was more going on than just the obstruction downstream, but not sure what.
Anyways, keeping in mind that this install is on an island, and although we have no way of knowing for sure, that it was probably done when the house was built, how would the thing be vented? Inside the wall? Vented as above (which I doubt since that is definitely not an idiot proof way to do it)? Or could the vent be obstructed in some way? I mean, the sink works now, from both sides, but we have a sneaking suspicion that it isn't "right". I don't want to call a plumber if the problem might be simple and easily accessible.
The vent is not the problem and if there, it is on the downstream side of the trap. The sink outlets would not act as a vent.
6t7, that is a possibility I guess. Only ways to know would be to either open the wall or get a scope in there. Another thing that is weird on this house is that I cannot find a cleanout anywhere on the outside of the house. And I did not see a readily apparent main line cleanout either. All our other houses (similar age, same city) have those two cleanouts. There was a cleanout right under the kitchen sink drain line. In any case the thing is working now, and seems to be working well enough, so I guess we wait until something else happens, and at that point we might call our plumber.
why not save yourself a lot of time and just install an auto
air vent under the island sink.... its not worth trying to figure out
what went wrong with some old vent going up some wall....
just add an extra auto vent
An "island sink" does NOT have any wall that the vent could go up, so it either needs the "island drain" piping, (or a pipe running up through the room into the ceiling), or an AAV for a vent. Or do you mean the sink in in a "peninsula" in which case the vent probably does go up the side wall. One sink does NOT vent the other one because any vents are AFTER the traps, NOT in the sink.
Last edited by hj; 02-03-2014 at 05:27 AM.
Licensed residential and commercial plumber