Clio 2002 central locking problem

Hi guys and girls :) New member here with a problem that seems quite common although I've not really been able to find a solution using the search function.

I bought myself a nice little 2002 Clio 1.5 DCi last weekend but unfortunately the central locking doesn't work from the key fob :(

When I press the button no light emits from the fob. I've changed the battery. I have to manually unlock the drivers door then press the button on the dash to unlock and lock passenger side and boot. From searching the forums I've come across all sorts of information but I'm a little confused :confused:

I thought it would be a cracked/loose connection in the key itself but I just phoned an auto electrics place near me to see if they could do it and have been told it's not the key fob because the key when put in the door isn't unlocking all the doors/boot through the central locking but on searching the forums I've found that it wouldn't do that anyway?

I've looked about having the key repaired (as I have no idea what I'm looking for inside the key and can't solder anyway) but then I'm reading about the key needing programming?

Any help would be much appreciated! Thank you in advance :)

Clio 2002 central locking problem