The driver's side heat only gets a little warm. The passenger side gets very hot and the rear gets very hot. I have replaced the thermostat and flushed the cooling system. Removed all air from the cooling system. Checked and verified the operation of the driver side and passenger side heat door controllers and they are fully functional. When the driver side heat door controller is in the full heat position it is only putting out warm air, not hot air. I don't believe it could be the heater core since the passenger side puts out very hot air. The new thermostat is from Honda and I used Prestone Honda brand antifreeze. Any ideas are greatly appreciated.