No Heat

I think I know what the issues is, but I want to get a second opinion before I go out and replace it.

I have no heat coming out of my vents. Once the vehicle is warm enough and the heater/blower is off, I then turn it on and some heat comes out and then it becomes cold. I know back in the 80's when I used to a 1979 and 1980's cars I knew it was a thermostat issue and it was easy to replace. The last time I replaced one was back in the late 80's. So am I right is it a thermostat issue and if so is it easy to replace in a town and country, I haven't looked yet.

I think I know what the issues is, but I want to get a second opinion before I go out and replace it.

I have no heat coming out of my vents. Once the vehicle is warm enough and the heater/blower is off, I then turn it on and some heat comes out and then it becomes cold. I know back in the 80's when I used to a 1979 and 1980's cars I knew it was a thermostat issue and it was easy to replace. The last time I replaced one was back in the late 80's. So am I right is it a thermostat issue and if so is it easy to replace in a town and country, I haven't looked yet.

I found out the problem. There wasn't enough fluids, filled it up and so far it's fine. I hope.