heater blowing out cold air replace thermostat

Hello, although an engine thermostat sticking open will never allow the engine to reach proper operating temperature efficiently, it certainly is not the only reason you have no heat. First, after replacing the thermostat, did you purge all air pockets out of the cooling system? Air pockets create spaces that prevent heat from blowing. The other thing is have you checked the climate control system to see if there's a concern inside the vehicle? There are temperature blend door motors that direct hot and cold air as desired. The controls and these motors could be suspect. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops