Thanks gts. Its actually locked in the memory settings though.
acorn. I actually got in touch with the installer and he's not interested. 
Spoke to the small claims court & now i am getting another engineer to change the unit then claiming it back plus £30 court fees.
This also gets a ccj against him.
I've also left a bad review on Yell.com
Thanks though guys
                
 keith
                
 February 2013