Demist or not as the case may be....

R

rosewhite

Member
Hi All,

It's that time of year again when the demist button comes into use on the front windscreen but why oh why does mine mist the whole windscreen up the minute I hit the button?? It done it last night at 70 on a dual - luckily the road was relatively clear.

Would appreciate your advice - could it be a fault or is it (more likely) user error!!! Many thanks
 
My apologies for sounding really stupid but I don't know the difference between air con and climate control!! The control panel has an "econ" button between the front and back demists, temp + or -, recirculation "arrow", "auto" and "off" - not sure if this helps??.

Thanks
 
it's climate. There ís only climate in the A2, no seperate Climate.

So, you press the button and everything mists up? Recirculation button pressed? Econ?

Bret
 
Audi climate control (ie. you set the specific temperature and the system maintains the temperature automatically) has air conditioning (ie. a little refrigerator that dries and cools the air) as part of how it works.
It sounds to me as if you have air conditioning, which is good! (Some A2s don't have it, they just have a normal fan and heater with rotary controls, which means you can only cool the car to the temperature of the outside air).
 
Thanks!

I have made sure everything else is turned off when i press the demist (but also have tried it with everything pressed as well!!). Nothing seems to make much difference - the mist just totally covers the screen within about 2 seconds flat. The colder/wetter it is outside the worse it is
 
rosewhite said:
It's that time of year again when the demist button comes into use on the front windscreen but why oh why does mine mist the whole windscreen up the minute I hit the button?? It done it last night at 70 on a dual - luckily the road was relatively clear.
Click to expand...

Are you sure it's not co-incidence - windscreen starts to get condensation so you press the button but it continues to get condensation?

In past winters I've had sudden misting of the windscreen where I go from visibility to can't see a thing in a few seconds. I never got to the root cause but it seemed to occur when there was a sudden drop of temperature outside to 3 (or was it 5 degrees). E.g. when climbing uphill to higher ground. Apparently there's a sensor that does something at this temperature (shuts the vents or something) and the knock on impact is the sudden misting.

Switching on the fan at full blast does eventually clear it but it's a tense moment and I'm frantically trying to gets some tissues to wipe the screen (as well as hitting the brakes!).

Next time it happens I will also press the front screen demist button (as I think that switches on a heater) as well as put the fan to full speed.
 
Alan_uk said:
...In past winters I've had sudden misting of the windscreen where I go from visibility to can't see a thing in a few seconds. I never got to the root cause but it seemed to occur when there was a sudden drop of temperature outside to 3 (or was it 5 degrees). E.g. when climbing uphill to higher ground. Apparently there's a sensor that does something at this temperature (shuts the vents or something) and the knock on impact is the sudden misting...
Click to expand...

I had one incident of sudden misting too! I was driving along the M40 (it was cold winter) and suddenly the traffic slowed down and it was all white in front. I hit a sudden local snow storm! I've always have CC on and the interior had been warm, cozy and dry. My front screen started to mist up badly and very quickly, I turned on the de-mister and it made it 10x worst initially! I couldn't see anything! I was literally sweating and surely increased the moisture somewhat! But eventually the screen cleared up but that was after 5 minutes.
 
Thanks for the advice folks, I am having a service next week so will add an a/c service too.

There is defintely no internal leaks/dampness anywhere and the misting is as described in the posts above - literally 0-full screen in 2 seconds as soon as the button is pushed. It then starts to demist immediately but that's no help when the misting is 10 times as bad than before the button was pressed!

I seem to remember when we had the snow last year it took forever and a day to clear the internal misting/freezing so perhaps it is generally "poorly"
 
I've not hit anything like this, but then I tend to avoid the demister button anyway....

TBH, it's possible that the condenser turns off at this point (i.e. 5 degrees) and that's why there's a lot of damp air around.

Cleaning the inside of the screen may also help reduce the amount of condensation caught.

Bret
 
Hi Rosewhite,

I too have experienced sudden misting up, but only when the temperature outside has been low single figures.

For everyday setting I suggest that you only have the AUTO light lit. This should help to keep the cabin low in humidity.

To check that the various motorised flaps are working correctly I suggest that you take the car for a run until the engine is at working temperature, then find somewhere safe to park up with the engine running. On the right hand side of the air con panel are three buttons arranged vertically for manually sending the air up, sideways or down. Starting with the just the AUTO light lit, press the top UP button. The auto light should go out and the UP light should be lit. You may briefly hear a faint whirring sound as the flaps adjust and with your hand you should feel air coming out of the windscreen vents. Increase the fan speed if necessary. After about thirty seconds press the AUTO button again and the air direction will revert to its original setting.

Spend a while pressing the middle button, wait thirty seconds, then back to AUTO, press the bottom button, wait thirty seconds, press the AUTO button. All this is doing is giving the motorised flaps a bit of a workout as they can get sluggish if not used often. It may help to set the temperature to MAX and the fan speed to MAX while doing this. Do this once a week or so.

Never have the recirculate button lit while trying to demist, but you may want to add it to the workout described above.

Hope this helps,

John.

PS Oh and make sure the inside of your windows are spotlessly clean.
 
Last edited:
ha, I had something tonight I've not seen before and it's not pleasant.

I'd had the car plugged into the mains and it should, therefore, be at around 60 before I even start. Fair enough, my climate decides it's time to blast air at me. I'd had something like this last week. Thing is, after a few hundred metres, it should have been at least warm and it wasn't. huh? If I set the climate to HI and up, then I get hot air. On Auto, cool. huh?
After restarting the car (I went to check some stuff out for my sister-in-law), 21 is held with four bars, as I was expecting.
I knew that the redirector to the floor wasn't working properly but now it looks like the entire warm air system might have a dodgy flap.

Why I write this? You really, really should check that all the flaps in the system are working the way they should. It might be that your demist is only dumping a certain amount of air in the right direction and therefore you don't get demisted as fast as it might.

Bret
 
I changed the central flap yesterday (2 hours of work and most of that was working out how to get the damned thing back in) - and hey presto, life is back "in Ordnung". I didn't realise how screwed up things were, but now it's excellent.

All of the flaps are the same inside and can therefore be swapped out at will. If you have any problems with misting on the inside: get these checked out.


Bret
 
I *think mine is ok but it sounds worth checking (adds to llist for summer).
I had/have one tiny patch that sometimes mists so I've left a sachet from a Beef Jerky packet there & it seems to have sorted it:eek:
 
Hi Bret. Sounds like a good piece of work. Now a "how to" guide might be very welcome for a few of us with demisting problems. hint hint ;)
 
I checked my filter after I bought my car a month ago (once I found it and worked out how to remove it).. half a forest fell out along with a birds nest... it was also 'damp'... I vacuumed and cleaned as best I could and found an immediate improvement in airflow from the vents and also the demist function..

New filter arrived today and I swapped out.. also found the original filter was installed the wrong way around.. not really sure what impact this has in reality but this is now also corrected...

Cleaner new cabin filter = not damp and much better airflow... big improvement from a small amount of work
 
You must log in or register to reply here.
Back
Top