Heater fan - low output

[shail]

What could cause the heating fans to have a low output?

Blower motor is working, and gets faster as I turn the speed knob, but the actual amount of air from the vents is poor.  Sometimes it's very poor and other times it's just about passable.

I've checked pollen filter and it's not dirty. 

Any other ideas? Has a pipe come loose somewhere?

[pudding]

Check the HVAC controller with VCDS to see if there are blend door actuator fault codes.

The vent output on MK5s is crap when fully operational anyway, imo.  There's no appreciable gust of wind from the vent(s) unless you close them all except the one you want.

Whilst on the subject, what is the vent above the hazard light switch for?   I've seen other MK5s with just a storage tray there, but mine has what looks like a speaker and a vent knob.  Never used it as it makes bugger all difference open or closed 

[shail]

It top vent apparently directs air upwards and closes the two top middle ones.  When I try it it seems to do nothing as well!

Not got access to VCDS but a Bluetooth scanner I have shows no codes. 

[pudding]

Same.  No faults on mine.  I think it's just how they are.  My MK4 R32 was the same, no guts at all from the HVAC.  Pretty poor A/C as well.  It's just how they are.

All of it is a lot better in the MK7, fwiw.