Heat

With the engine at full operating temp, locate the 2 heater hoses where they go into the firewall and feel them to see if they are both hot to the touch.
If you find that they are both too hot to hold, then the heat in that vehicle is controlled by a blend door that regulates heated air flow. it is operated by an electric motor/actuator. The problem can be that the actuator is stripped or inoperative or the door itself could be damaged. This is what needs to be determined by examining the actuator and see if it is responding to heat change commands or not.

Only one of my heater hoses get warm but not to hot to touch and the other one stays cool. Thanks for your Replies back

Compare that temp with the upper radiator hose to see if the engine itself is getting hot. If it is, then you have a plugged up heater core. You can try removing the heater hoses and flushing with a garden hose but don't get your hopes up on that. It will probably need a new heater core.

I have a 1993 Caprice with basically the same problem. One added detail is that during the summer I've turned on the heat and it blows hot air as I would expect. I've replaced the hoses leading into the firewall at a local shop with ASE certified mechanics. Heater core was replaced about 3 years ago and the problem started then. The temp gage on the dash does not go above the "1/4" mark.