Hello, I have a 2001 Ford F-150 4.6L V8 and I have a problem with the heater.

The truck seems to only throw cold air until the engine warms up completely and I am accelerating then it will begin to throw warm air. It sometimes takes up to 20-30 minutes before I start getting warm air.

Any help would be greatly appreciated...I'm freezing my *** off over here in the 50 degree weather in Texas. I'm not built for this weather

 

Check the temp of the heater hoses. If both are hot, the problem is the blend door.

If only one or neither is hot, coolant isn't flowing through the core.

 

Yes both hoses were hot. I was afraid it was the blend door now I guess I got to fix it.
Thank you for the help