Try downloading the LG support tool and install it on your computer! Once it has detected your phone it'll prompt you if an official update is available for your version, if yes continue the process! As far as I heard they'd stopped the updates due to some bugs but hey there is no harming in checking out!
Don't try to update your phone with a custom recovery installed since it'll soft brick your phone!
Or the last option is that you install a custom Rom of 4.4.2 and maintain your rooted status!
Sent from my LG-F240S using xda app-developers app