2011 heater problem

[RedDye]

Not long ago my heater stopped working. Still blew air but it was cold as hell. Took it to the dealership and they said the blend door wasn't working properly. So they replaced it and it worked fine for about 3000 miles. Now it's back to the same problem. Sometimes it works and sometimes it doesn't. Sometimes it just blows hot air and nothing else. Seems that sometimes whatever temp you have it set on when you start the truck is what you get for the day. Pulling over and cycling power on the truck sometimes will get it to work and sometimes no change.

So saying that, did I just get a faulty new blend door installed, or is there something else to consider.

Thanks

 

[coorsman2005]

head gasket will do that to puts pressure in the system and keeps coolant from flowing through the heater core that was the first sign of my hg wish you the best though

 

[ShibbyUTman]

What does your overflow tank look like? Full/Empty about right?

 

[RedDye]

Right where it is supposed to be.