I have a 2003 v6 Accord and the heat does not work. I ran the diagnostic test and it did not give me any error codes. The heater control valve is working and the passenger side blows luke warm air but the drivers side is cold air.

Anyone have any ideas on what it could be?

only has 111000 miles I hope its not the heater core!

 

how does coolant look. if its rusty........ could be plugged heater core. sounds more like blend door inop. check heater control valve on firewall passenger side.

 

i think it is the blend door the heat on passenger window is very hot then as you get closer to the center vents it gets colder

thanks for the info