defrost problem with LG thermaV

[pbo]

our three different thermaV just work fine, however defrost cycle only starts after a long while. the units are then already complet iced over. 2 or 3 houres are not uncommon. our installer is gone..no support from anywhere...any help or advise very much welcome..thanks

[install monkey]

http://www.mediafire.com/view/?vvuzv3mb7xcoshv no mention of defrost settings but maybe interrogate for a fault code- may just need filters on indoors cleaning