We have made an addition to our house by expanding our kitchen. The new sink was roughed in by a professional plumber. Now, 3 years latter; I'm finishing the project and trying to plumb in our sink drain. The stub-in sits level with the sink's base; and there is a studor vent in the exterior wall. I can't get the sink to drain and have three concerns:

1) With the studor vent being in an exterior wall is the insulation preventing the vent from breathing enough to drain? (there's absolutely no drainage; I'd think if it's the vent there would be a slow drain?? )

2) With the stub-in being equal in elevation to the base of the sink drain do I have enough gravity fed pressure to evacuate the water from the sink through the p-trap?

3) Over the three years the rough in sat open, has the drain line become clogged with debris?

I think #3 is the least likely, the rough-in sat open in construction dried-in conditions. So, it hasn't been exposed to the elements for all this time...

Any suggestions?

The stub out should not be on the same level as sink base. It should sit lower. We rough it about 17" on center from rough floor. But in some cases (when using deep triple bowl sinks or farm sinks ) even 17" is too high. I would lower it few inches.

That drain my definitely be clogged up after 3 years of sitting there open. Snake it.

Vent would be the last thing I would look at.