When I turn off my heat their is still heat coming out of the vents. Is this normal for my 02 Blazer 4x4 LS?

 

you turning off just the fan or turning the heat down to cold? If you leave the thermostat on high you will still get heat

 

in my 98 i dont have to run the a/c much (thanks to cali weather) and i still get spurts of hot air that come out. the **** is almost always on cold, but the heater core is under the dash and the evaporator core is under the hood. so you are always getting a little heat. i even put mine on re-circulate and still get a little. normally not a big deal, i just kick the a/c on and blow the hot air out and shut everything off again. stays comfortable for 20-30 mins depending on how much i am driving.

 

That sounds like a blend door issue. I would do some searching here on the Forum to see if any of the other blend door problems are similar to the one you're having.