I’ve booked it into the dealers for a check on Monday so I will report back how we get on 

Quick update, haven’t had a chance to test it properly yet as just back from the dealers - apparently there was a wire trapped/snagged somewhere, they found a stored fault code. Something to do with recirculation flap.  They have repaired it ? Details were a little vague and the dealers were in full COVID mode so didn’t want to pester them too much for info. Will test it and report back . 

23 hours ago, Pe09 said:

Quick update, haven’t had a chance to test it properly yet as just back from the dealers - apparently there was a wire trapped/snagged somewhere, they found a stored fault code. Something to do with recirculation flap.  They have repaired it ? Details were a little vague and the dealers were in full COVID mode so didn’t want to pester them too much for info. Will test it and report back . 

 

Sweet, glad that it sounds like it's sorted for you! 

So after a few days testing, everything is now working as I expected it too. No weird bangs and a nice cold blast of air on demand. Hopefully I’m the only one who it happens too but at least the video might help others. 
Cheers for everyone’s input. 

Sorry to reawaken this thread but I wondered if anyone else had seen this issue?

Occasionally when driving in hot weather my mk 3 Octavia 2.0 TDI will have the exact symptom of really low power air coming out the vents no matter what setting I put it on (although you can hear the blower working hard if you put it on full but still no air coming out), then randomly I went round a roundabout and it came back on full chat

I had orginally thought it was the blower starting to fail or the evaporator freezing over and blocking the vent but I'm considering it might be a flap issue?

7 hours ago, Pindadio said:

Sorry to reawaken this thread but I wondered if anyone else had seen this issue?

Occasionally when driving in hot weather my mk 3 Octavia 2.0 TDI will have the exact symptom of really low power air coming out the vents no matter what setting I put it on (although you can hear the blower working hard if you put it on full but still no air coming out), then randomly I went round a roundabout and it came back on full chat

I had orginally thought it was the blower starting to fail or the evaporator freezing over and blocking the vent but I'm considering it might be a flap issue?

@Pindadio same thing happened to me, driving at 30C outside, suddenly the air dropped to a trickle. I went manual and move the blower to max, temp to LO, recirculate, tried changing flaps direction to front, feet, windshield. Nothing would make a difference. I could still hear the blower super going like crazy, but almos no air coming out, as if all flaps were closed.

I was (am) just so puzzled.

@prosist I would send a private message but can't as a new user... Did you find a solution? I have posted recently on two other threads on this site, I have same problem on 2020 Mk4 Octavia, and seems to happen when it is very hot (i.e. when you need air con the most!). Web search shows it happens on other VAG/VW cars e.g. Golf, and older cars. I am fairly sure it's a software/control fault, although possibly a sensor. Someone helpfully posted a workaround where you initially set the temperature high (e.g. 28) then gradually reduce it as the cabin cools down. Annoying esp if you're driving and have to keep touching the screen, but worked yesterday. Other thing I found (and others) it's triggered by putting car into reverse, this could be intentional switch to recirc to avoid exhaust fumes entering but potentially its only closing off the outside vents not opening the recirc vents, and then not switching back to external when driving forward. All very bizarre.

I have not find a solution yet. Thank you very much for the added info!

I've not had the issue again since it happened back in June, I am convinced it's a software thing too. I've noticed that the recirc vent above the filter closes when you press either the AC button or the recirc button, but when my car was in fault the vent wouldn't open or close when pressing the AC button.

Did you fixed it or just didn't happen again?