Need a picture of heater core hose arrangement. Had a hose bust, replaced with new hose set but no heat now. I may have got them in wrong order. Cannot find a decent diagram or pic anywhere. 2010 ford flex limited

 

In either case the heater core should provide heat,,,,unless,,, it has air trapped inside and the coolant can't circulate through the core. Efficiency would be slightly reduced if hoses are reversed, no big deal.

If you can , do this with the engine not HOT !
With the engine idling , loosen the highest or return hose ,just enough to allow the air to come out and some coolant too, then secure it and that will allow the trapped air to escape. Should take care of the problem,,,,,provided the thermostat is functioning correctly.