[a2-16v-list] Help! No heat!

[Brian Wilkeson]

Ahhhhhh, the best time for my heat to crap out.
 
Car:  92 Passat 2.0 16v
 
Problem:  No heat...engine running hot.
 
 
I had a new radiator, water pump, and hoses put in a few months
ago..whole system flushed and filled with new coolant.  What could be
the problem?  Am I right to assume that if the heater core went that I
would be able to smell coolant/some would leak on to the passenger side
floor?
 
The reservoir is half full of coolant.
 
 
Any help would be great!