2000 Ford Taurus Heater doesnt work?

First, check the water/anti-freeze level and be sure the radiator is full, try doing this at the radiator, not the Reservoir tank. Be sure engine is cool.

If, the fluid level good, you may have a valve stuck (There a valve in the Heater Hose or somewhere turn the water on and off through the heater) or Vacuum hose problem in the Control Panel.

The positon of the heater core in the Taurus makes it prone to sedimentation. Feel the hoses with the engine warm and the heater on. One will probably be much warmer than the other. This indicates the core is plugged up.

Remove the hoses and flush the core out from each pipe with a garden hose until all is clear.

Hope to goodness the core is not bad! To replace you have to pull entire dash and discharge the AC!

You may have a bad heater control valve. Follow the heater hose coming out of the firewall to find it. They can sometimes be controlled by hand. Check for vacuum/cable connection problems.

well there is what is called Tech service bulletin for that what happens is water leaks into the heater core through the cowl on the outside it leaks down into the blower motor and the blower resistor and it stops working. If the blower motor works and you still don't have heat you need to check your coolant if it is low you will have no heat if the heater only works on high then you need a blower resistor

Depends on exactly what heater does. If heater is blowing air, just not hot air, could be the thermostat or low of coolant. If not blowing any air, check fuses first, if fuse good, most likely the blow motor or the switch inside the cockpit.

If the heater hoses are at EQUAL temperature, when it's warmed up to operating temperature, it sounds like you have a blend door, or blend door actuator issue.

change the thermostat first,then flush out the cooling system,but it sounds more like the thermostat is bad.

get a new car