I believe the drain is plumbed in to the skimmer, but when I bought the house there was no skimmer basket or float valve assembly. I am wondering if I bought these if the drain would turn on (from the random thins I read on the internet). The pool was resurfaced last year and they even replaced the main drain cover, so that makes me think that it must still work or why would they replace the drain cover.

Another Question: What is the threaded higher up port in the front of the skimmer (pic below)? They have the sweeper connected to the back lower port via some piece of elbow PVC.