How can i fix my LG WM-16225FD?

My washing machine (LG WM-16225FD) is about 3 years old but is refusing to take fabric softener out of the drawer, there aren't any blockages though as i have tried pouring water into the drawer and it came through into the washing machine, i have had a washing machine technician out but he said there is nothing wrong with it but there is as the washing machine will not take fabric softener, any ideas on how to get it working?