Ford F750 with Caterpillar engine has no heat?

Ford F750 with Caterpillar engine has no heat? - 1

Added (1). Took off both heater hose lines and both have coolant flowing out of them. I think this is an issue but what is the cause?

Added (2). Thermostats seem ok. Coolant is full. Engine reaches normal operation temps of 180 range.

Added (3). Heater core is not restricted. The key here is I have hot coolant flowing out of BOTH heater lines going to the heater core. Should only have coolant flowing from one of them.

Bad hemostats. Low on water checks these this is where Id start.

Check the heater core to see if its blocked and no fluid actually flows through it. The heat door in the air flow may also be closed or blocked -- and i've seen one where the air duct was blocked because some rodent had built a nest in it.

If both heater core hoses are hot when the truck's warmed up and the heater is on, you have an air flow issue. Most likely the blend door. It could be stuck like Spock (rhp) said or the actuator is bad.