How do i replace the heater control valve on 2000 Ford F-150

The heater only gets warm. but the hose going into the core is hot and the return is only warm

Asked by for the 2000 Ford F-150
No heater control valve on this vehicle. I am concerned that you have a possible restriction, though, since you have hot going in and warm coming out. A back flush of your heater core is the best first step.