W205 a/c problem

[fourwheels]

Do I have a problem with my 2016 W205 C-Class A/C or is it just a strange design feature.

I usually have A/C on Auto and set to 19 deg (which directs air flow to face and feet).
Few weeks back noticed colder air (maybe 17 deg) around our feet. Not a blast, more a draught.
Main Dealer applied a software fix which they said was for similar issues.
Now we find there is little or no air flow going to the feet when in Auto.
If we come out of Auto and toggle the manual switch to feet only and turn up the fan speed, we get a blast. But of course then we lose air flow at face level.
Visit to Dealer today and took a look at a 2018 c-class which to dealers surprise seemed to be the same.
Seems odd that on a long hot drive you can't have a sensible air flow to both face and feet.
Up to a few weeks ago I had never questioned any of it in nearly 3 years of ownership.
Would appreciate comments from anyone with similar car.


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[Wabby]

Is the car in ECO mode as well?

I'm pretty sure I have seen the setting in mine that when in ECO it turns the A/C to like a hamster blowing on you!
Just a thought.

 

[fourwheels]

Is the car in ECO mode as well?

I'm pretty sure I have seen the setting in mine that when in ECO it turns the A/C to like a hamster blowing on you!
Just a thought.

Thanks Wabby.
No it's on Comfort, air re-circulation is off, s/s is on (although I've just tried off, no different) have just read though that with s/s on a/c function can be reduced. That's not the problem though.
Reduced, non existent, air flow to the feet is the problem.
Just carefully gone through all settings. Auto seems to cut off flow to feet.
Ok, you can direct flow to feet and increase flow to max 7 (but that cuts off face level flow). Switching back to auto reduces flow and cuts off feet.
Lots of chat in the book about automatic control but nowhere does it tell you how it controls flow in auto.
To recap:
Just done 7 mile journey over 22 mins.
Outside temp 20.5 C
Inside set to 17 C Auto
Set to Comfort, s/s working, all windows & roof closed, (tried with face vents open and closed).
a/c fan blowing like mad for entire journey, face level air flow but nothing to the feet.
In contrast though on the outward trip it was blowing to the feet, weak but it was there. Didn't change anything other than starting and stopping before returning home.
I didn't notice this problem over last two years.
Dealer didn't help because as I said in a 5min used car demo, it didn't blow to the feet which left both of us confused.
Well i'll be in Spain next week, I hope whatever I have there blows to the feet.



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[CaptainChaos]

Auto will distribute the air as it sees fit, dependent on conditions inside and outside the car. But if it's suddenly doing something it's never done before it suggests one of the flaps inside the ducts is misbehaving and not allowing air out into the footwells.

 

[fourwheels]

Auto will distribute the air as it sees fit, dependent on conditions inside and outside the car. But if it's suddenly doing something it's never done before it suggests one of the flaps inside the ducts is misbehaving and not allowing air out into the footwells.

Thank you. Yes that was my original thought. Service guy at MB said they couldn't reproduce a fault but there was a software update which they applied.
I think I have to argue this one out with them.
I assume there's no easy way for me to get to it. Car still under warranty.

 

[BMF]

It maybe working on the principle that cold air drops and so it senses the low temp in footwells and distributes the airflow elsewhere automatically.

 

[fourwheels]

It maybe working on the principle that cold air drops and so it senses the low temp in footwells and distributes the airflow elsewhere automatically.

That's possible but for at least 2 years we didn't question it. It stayed on Auto and I don't think we changed the temp very often. Perhaps in the coldest winter or hottest summer.
In fact now you draw my attention to it - we had a very hot summer last year - for a very long time and we didn't question the aircon, it just worked.

 

[BMF]

That's possible but for at least 2 years we didn't question it. It stayed on Auto and I don't think we changed the temp very often. Perhaps in the coldest winter or hottest summer.
In fact now you draw my attention to it - we had a very hot summer last year - for a very long time and we didn't question the aircon, it just worked.

I too have W205 (a C220) and the aircon is on all the time and I think this is how mine works. I also had a Vauxhall Insignia and the aircon was on auto for the 5 years of my ownership and it worked the same.

 

[fourwheels]

I too have W205 (a C220) and the aircon is on all the time and I think this is how mine works. I also had a Vauxhall Insignia and the aircon was on auto for the 5 years of my ownership and it worked the same.

Thanks for your comments. I'm going to have to leave this for a while but it will give me the chance to look at friends cars etc. Now it's crossed my mind I can't think why we didn't question it last year. Possibly there is a fault, or the software update changed something maybe along the lines you describe.