2008 Sport Trac Vents go warm but not HOT!

[Pharbach]

With engine warmed up, selecting ANY vent exit, when temp set to HOT, it only is warm and NOT hot. Takes loads of time to "defrost" moisture on windshield in defrost mode. Air temperature is too low to get it all in a reasonable time.
Is it a blend door problem? If so is it actuator controlled? Is it an easy/expensive fix?
Thanks!

 

[blert]

I would suggest first performing a flush and back-flush of the heater core, they do get clogged up. Simple procedure that could very well solve the issue without digging in the dash.

 

[Pharbach]

Cool!
Didnt think of that!
I will try it!
....if it's not that, could it be a blend door problem mixing too much cold air with hot air?

 

[Phil Frady]

It could be the “Max A/C” valve. It’s on the line going to the core and shuts off coolant flow when you select Max A/C. It’s possible that it may be stuck closed or partially open.