[Dick D]

I found a vent pipe that went straight to the basement. I then drilled a hole on the roof beside the vent pipe and fished the wire down beside it.
I then re caulked around the vent pipe and that made a nice clean, neat job. I didn't have to drill too big of a hole as there was already some space around the vent pipe to start with.

On my rig, several of the vent pipe's went directly to the tanks. They were inside the wall and out of sight.