Hi Gang, I'm new here. We have a 6430 Premium that only blows warm to hot air. All functions work, fan control, selector switch ( defog, feet, ect) I pulled the seat and accessed the heater and air conditioner condenser and found that the lines on either side of the valve are always hot once operating temp is reached. In my opinion this would indicate a faulty valve. I was told by a JD mechanic that it probably has a faulty Climate control unit. Ours DOES NOT have the Climatrack controls. Just a simple 3 knob unit. I got a new control unit and plugged it in and no change. Now Im told that the unit needs to be calibrated. Really. Is this true. I dont want to pay someone to drive 2 hrs to our place and then say well I guess it is the valve. I guess my real question is, do the simple 3 knob control units have to be calibrated and can it be done through the tractors command center or do you need a special JD program n a laptop.