Starting to play with new truck

[SS317]

So I finally get her delivered this morning. I charged up the battery, checked the fluids, put on a new radiator cap and started her up.
She was a little cold blooded at first but finally got warmed up enough to idle really nice. Everything is going well. I go feel the radiator hoses to check if they are getting too hot, they are good. Temp gauge is moving a little bit.

I notice the gas gauge hasn't moved. Ok, first thing on the list, check wiring to sender, possibly get new sender ordered.

I think to myself that it's a little cold. I turn on the heater, it's blowing nice and strong. I wait for it to warm up,,,, wait,,, wait some more,,,,, keep waiting. I start to play with all of the levers to see if I just need to learn how to operate them.... no joy. So now I think I better look a little closer. Check out the pict. I'm pretty sure this is the heater, and no lines are going to it. See the nice loop the previous owner did to keep that fluid flowing from the water pump....

Any way I can save this heater or do I need to order a complete new one?

Sean