so I bit the bullet and bought a 2013 f150 xlt with 43k on it. Never owned anything so nice!!! ( Ive only owned high mile beaters till now) anyways this problem has happened 3 times now. The temps here have been in the single digits so I start the truck to warm it up. When I get in it to go, it's cold in the cab. Truck is up to temp. Heater is blowing cold air. If I cycle the temp control all the way from full hot to full cold, wait a second and put it back on full hot it'll blow hot air and work just fine. It has done this leaving it on full hot when I park the truck. First time it happened I checked the coolant (which is full) and both heater hoses were hot. I seen there is a blend door issue but I don't have any strange noises coming from the dash

 

Are you using a remote start or starting with the key?

Do you have the manual or automatic climate control?

 

No remote start, started with a key. And it's the manual heater control