Hmm, looks like you didn't have it screwed in properly.

Either that or the print detached and the filament just built up on the nozzle.. never had a loose nozzle, plenty clogged by a detached print - though, it has to be said - not recently :-)

Personally I;d stick to the original wanhao parts - they generally use decent kit.

And you'll not print anything over 300c without building a serious heated build volume first anway.