So I followed Flashforge's video on cleaning the nozzle: https://www.youtube.com/watch?v=2Sm5hXN3mMg

It's printing at the moment, which is great news, but I don't think this is the fix to the underlying problem. I managed to get a print out last night after loading and unloading filament about 5 times. Could the root cause be something as simple as the nozzle needing to sit pre-heated for a few minutes prior to a print if the printer has had chance to completely cool?