2002 Sebring started overheating right after thermostat replacement?

You have air in the system since you replaced thermostat. To bleed leave over flow cap off add anti freeze to full level start vehicle let idle anti freeze will start to fill up over flow tank that is why you leave space in over flow tank and leave the cap off for this to happen once vehicle reaches operating temperature the thermostat will start to open and level in tank will go back down add anti freeze to full mark and put cap back on.

Let is cool all the way down then restarted with cap off up to running temp. Coolant lvl never went down, just started boiling before the gauge got to halfway between the C and H. Did notice that the top hose was very hot but the bottom hose never seemed to change temp.

What was the reason that you changed out the thermostat ?

Because it sounds like the thermostat is not opening up.

Didn't, girlfriends dad did it before he went back home so she wouldn't have problems over the winter.

Did you install the thermostat correctly it is easy to install the wrong way.

I was hoping that wasn't the problem because this car is a pita to get to that thermostat so i'm doing a process of elimination before I go there...some post said it may be in backwards...

spring is supposed to be toward the engine correct?

Is it a four cylinder or six cylinder ?

That is correct spring goes towards engine.

Yeah it sounds like it's it installed backwards.

Then that's that guess i'm tearing it apart Sat. Will let you know and ty for all your help so far.

Ok Thanks will appreciate the up date.