Weird heater fan issue 20 plare fr

[dsj20v]

Hi all our 20 plate leon fr has developed an intermitten heater fan fault, basically it does what it wants from when the dial is turned all the way round the light blocks show its on full but no fan whatsoever, this was a real issue with the weather a couple of days ago as couldn't get rid of misting, also sometimes it will come on on its own, now I'm taking it into seat but as its intermittent they l won't have a clue if it is working at the time, just wondering if anybody else experienced this, cheers