Thread: Low heat

I have a 2006 grand prix, changed the water pump and runs great with no leaks,does not overheat,has full correct coolant level,thermostat is fine,but have only a little heat,when accelerating a little more heat is produced,blower motor is fine and heater core shows no signs of being cracked either,i am really stumped please help !!!!

I'm pretty new to grand prixs but I did have a similar issue with a grand cherokee and it ended up being a blend door motor that opens and closes the vents for cold or warm air. Not sure if these cars have a similar issue but maybe worth a check.