Ford 2000 Expedition no heat

Purge the air out of the cooling system.

Watch this ----- https://www.youtube.com/watch?v=nThsFGa1vuE

Thx--Purging the air from cooling system helped a little bit. Getting some more heat now (longer than 30 seconds) but not very warm/hot. In addition to the above video being helpful this video was also helpful as I don't have a radiator cap.--https://www.youtube.comwatch?v=Ffnhht1SjWQ Keep adding some coolant to the reservoir to maintain the level. What should I do next? Flush heater core? Keep purging air? Still no heat in the rear/rear heater core but rear AC works good.

U must have radiator cap because the system needs to be pressurized. It will pressurize itself once u start the engine and let it run a little bit. Bleed air from system by squeezing upper and lower hoses then opening the cap just a little bit until water and/or air come out until just coolant comes out being careful not to take cap all the way off. If u still don't get a hot heating core( hot air blowing) change the heater control valve( located under hood in engine compartment 3/4 inch hose running to heating core with the heater control valve in the line. Good Luck!

Cruze, Same here. Did you ever figure out the solution? I am planning to do the next flush with the appropriate coolant cleaning solution and run a lot of water through the system (water softener water). Many people have replaced the heater cores front and back but that does not seem the answer since there is flow through the cores when demonstrated by the videos that ow how to flush each one.