2009 Audi S5 a/c blows only cold?
 

So i was driving around and it suddenly felt colder inside the car. Turns out the a/c wont blow hot air anymore for some reason. Anyone has any idea what might be causing this? It literally happend just in the middle of driving, tried every setting possible, barely even warm air coming out on max temp settings.

Got it scanned, it was heater coolant shut off valve n279 with intermittent fault. Everything was working fine this morning but i'm expecting it to come back, luckily nothing too bad to fix.