Check the coolant level. My 2000 Ford Taurus has a constant flow cooling system and the heater will not work if the coolant level is too low.
If the heater is not working in your Eddie Bauer edition Ford Expedition, your heater core is probably junk and needs to be replaced.
The blower may simply have burned out. If the blower is out then the heater probably still works.
Probably a worn-out or clogged heater core.
No you probably need a new heater
Your heater core is leaking you probably also noticed the heater may not be working as well.
It is probably the heater coil. When it stops working water from the radiator goes back through a hose and when it overfills it emptys into the passenger side floor. You can replace the heater coil or bypass the hoses. Second option will cause heater to stop working.
if the rear ac is working then you probably have a damper door that is inoperative. this is in the heater/evaporator box. so if it isn't working then you will be heating and cooling at the same time out of the heater box.
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no
try the simple first: replace the thermostat, next flush the whole cooling system (not just radiator), if that doesn't work, you probably need a new heater core.
The heater on a Mercedes c200 will stop working if the heater core is blocked. It allows hot coolant from the engine to be used in heating the cabin.
If you have lost a sufficient amount of coolant this will stop the heater working because there will be no hot water in the heater rad.