Heater Control not redirecting air ?? help

I've recently bought a R reg 2.5 DT Range Rover and just found that the heater control doesn't redirect the air from the windscreen to say the foot well and so on - no matter which button i press it always blows to the windscreen. Can anyone advise what the problem may be. The buttons still light up when i selecting any of them, but just don't have any effect.. Would it be the control unit itself on the dash and can i upgrade it to a digital display type - just plug it in and go ?

Could be the distribution blend motor stuck or worse-shot.
Try selecting "Manual" mode and select floor setting, then select screen (Demist), you may be lucky and free it. Is the book symbol showing on the HEVAC display?

HEVAC Display ? whats that..? My heater control is the very basic one with 3 dials and buttons along the bottom with no digital display...

I was refering to the digital display option (Valeo).
If you do not have this, you can get the faults read by either a main stealer with Test Book or an Independant with Rovacom or Autologic.

maybe the hoses are blocked ....

i've read somthing about that on Range Rovers go there and check it