Startup Noise From Heater

Hi, I have a 2014 mk2 vrs. It has done 18k miles. I only use the air con every 2-3 weeks to keep it operational. Yesterday when i turned it on, there was a relatively loud clicking noise coming through the passenger vent area. This died down and disappeared. I turned the air con off and on a couple of times but couldn't replicate the noise. The next day when I started the car (from cold, with the air con off), there was a whirring noise coming from the vent (not clicking this time). Again this died away after about 30 secs. I turned the air con on and off a couple of times but again no further noises. It has now been a couple of days and it happens every time I start the car from cold. Doesn't seem to matter if the air con is on or off, the noise is there. At no point has the clicking noise returned. 

I have seen a couple of posts from Octavia owners who have whirring and clicking from the heating system but it tends to remain at all times... As I mentioned above, this noise dies away and is not there again until the next time I start the car from cold. I have also noticed that the accelerator is very sensitive. Sometimes you just need to touch the accelerator and the car jumps forward (from a stand still). I am guessing this is an unrelated issue (or even standard with this DSG?)

Cheers.