Which heater hose goes where?
 

On an 07 sti I don't know which heater core hose goes to the top connection at the firewall and which one goes to the bottom. I'm 99% sure I have the red and green arrows right, I just don't know which goes on the top or bottom. Been so long since I unhooked them, I don't remember. Any help would be appreciated.

I doubt it's changed since the '02 WRX came out. Check the FSM: http://www.seccs.org/tech

I'm trying to find an actual picture in the FSM for you... but it's turning out not to be obvious in there. :unamused: Even the instructions for removing the engine just say to unhook them without mention which is in and which is out.

I believe that the top hose flows from engine to heater core, and the bottom hose flows from core to engine. Really, the hoses are pre-formed with bends to fit properly just one way... can you just test fit them until they look "right"? Plus, if it's wrong, everything will still work... you're just pumping hot coolant through a heat exchanger... direction of flow shouldn't matter unless you're somehow putting undue stress on the water pump.

I just looked through there and found the same thing you did. Nothing, it just says to hook them back up. I could almost see in one of the pics, so I will give it a try how it looked in there. Them being preformed, yes, but it was just not lining up like I thought they would. Not the obvious way as I had expected. And I guess it should work either way. Thanks for the time, and thanks to whoever posted those back-up pdfs!