2005 2" Heat Vent goes to Where?

[RDuke]

Hello. My furnace has a two inch line coming off of it and going into the floor. Back by the bathroom there is a two inch line coming out of the floor which T's into the 4" line used to heat the bathroom. It looks like they wanted to add a little extra hot air to the bathroom. The problem is that when the furnace blows into the 2" line, nothing comes out the other end. Either it's crushed in the floor or I don't understand what the line is for. Anyone know? I've attached a pic.

Thanks

[CRH]

Are you sure it's not the hose used to heat the belly pan to keep the tanks from freezing?

[RDuke]

That could be the case. All I know know is what I originally stated. What's odd to me is that the fresh and grey tanks are mounted below the belly pan and running heat above them seems like it would do little good. Also, why would no air blow out of what appears to be the other end of the pipe coming out of the floor in the back. Is that system designed to leak air out the seams or something? It's a little crazy making not understanding how the system is supposed to work.

[dznf0g]

Yes the front 2" hose heats the fresh tank and the rear 2 " hose heats the black and gray tanks.

[RandyNH]

You say it's a 2005, that's a lot of time to build a nice nest in there.