My 2004 ford expedition has no heat.where do i start repair?

My 2004 ford expedition has no heat. Where do i start repair? - 1

Check your coolant levels, immediately before you drive it next time
Look for leaks
Most likely you have blown a heater hose

Check coolant IMMEDIATELY!

The same fluid that cools your engine provides the heat. If that is the issue, you will fry your engine soon and will no longer have to worry about the heat as the vehicle will no longer run and likely need to be picked up off the side of the road where it stalled and sold for scrap metal (which should cover the tow fees to get it off the road).

After coolant, check controls, but should get some heat when on vent even without the blower.

Check the coolant and the thermostat next. If both are up to snuff, then you have a ruptured heater hose or worse yet, heater core.

Check the coolant level, if low add. Coolant fine check for leaks, no leaks here are the causes for no heat.
1. Air in the cooling system.
2.Faulty thermostat.
3.Vacuum operated door actuators broken, missing vacuum source, or stuck.
4.Faulty heater core.
5. Worst case scenario blown head gasket.
6.Kink in heater hoise.
. If level is fine then try to bleed the system. There are alot of youtube videos on the procedure. You should have hot air.
. Checking the vacuum source for the air conditioner door actuator. There's a check valve in there as well, there's a youtube video on this with a expedition like yours.