driver side heating not working

Hi all,

the heating on my side of the car is not working, wasn't bothering me for a while, but as its starting to get colder and even frosty one morning recently it becomes quite important.

its a 07 VRS PD estate.

it heats on the passenger side but not drivers side.

error code I have is as follows:

"01810 Positioning motor for temp. flap r-V159"

anyone any ideas as to what is required to fix this?

thanks,

Martin.