How do you unclog heater core in a 2001chysler sebring

You can disconnect the heater hoses and flush the core by running a water hose so the water flow runs in one direction then reverse the hose so the water flows in the opposite direction.or you can with the hoses disconnected drain the heater core and fill the core with clr and let sit for about half to an hour then flush with water reconnect the hoses and fill cooling system and run car it should allow heat.if not try with clr again.if you clamp off the heater hoses before disconnecting them you won`t loose very much coolant.

If the core is clogged because of particles and corrosion you may just want to replace it. You will have to unhook the two water hoses to the core and backflush the core and that shjould push the stuff back out the inlet hose. The two lines are the ones on the back of the engine firewall.