[bomelia]

Well I will look at this tonight. I guess I am surprised that water can flow in one direction through the heater core, and yet not the other direction (at least that is what I am hearing). I do not think the thermostat is bad. I unhooked the bottom hose to drain the system. Then, after the radiator was empty, I started the car. After about 2-3 minutes, water started flowing out of the hose radiator again. Once it emptied, I was able to push water through the system via one of the ports on the heater core.

Mike