Why does heater always blow cold air, even when set to 78F?
Thread Starter
Super Member
Joined: Jan 2004
Posts: 538
Likes: 2
From: Silicon valley
Audi C7.5 S6
Why does heater always blow cold air, even when set to 78F?
Even turning off the AC switch, it still takes a long time before the heater will blow moderately warm air. The engine gets near 100C, but still only gets cold air, most of the time.
My S4 Audi heater worked way better than this.
Also my wife's Camry heater works excellant.
It seems like a programming problem with the AC/Heater control unit.
My S4 Audi heater worked way better than this.
Also my wife's Camry heater works excellant.
It seems like a programming problem with the AC/Heater control unit.
MBWorld Fanatic!
Joined: Jul 2004
Posts: 2,469
Likes: 1
From: Hong Kong
C55AMG W203; 330i E90
Can't tell why . My 35 years MB garage experiene friend told me the MB air cond auto design is based on mixing warm and cool air depending on change of outside and inside temperature. The C55 air cond that I have , will even take the sun 's radiation into factor. That's German style, they won't explain and that 's what they think it is good for you.
Every time I found the auto mode is too cold or too warm, I simply override the auto mode. Why bother to srcratch your head?
Every time I found the auto mode is too cold or too warm, I simply override the auto mode. Why bother to srcratch your head?
Super Member
Joined: Sep 2004
Posts: 694
Likes: 3
From: Bethesda, MD
Porsche
Sometimes when I drive I have the windows partly down with the heat on... What I find annoying is when the heat is on max it's blowing hot air (as it should), but when I move the knob one click lower the air is cool (even though it's still clearly in the 80s range).... The C32 also had the same problem, but I never encountered this issue on other climate controlled cars...
Eric...
Eric...
MBWorld Fanatic!
Joined: Jul 2004
Posts: 2,469
Likes: 1
From: Hong Kong
C55AMG W203; 330i E90
Originally Posted by EKaru
Sometimes when I drive I have the windows partly down with the heat on... What I find annoying is when the heat is on max it's blowing hot air (as it should), but when I move the knob one click lower the air is cool (even though it's still clearly in the 80s range).... The C32 also had the same problem, but I never encountered this issue on other climate controlled cars...
Eric...
Eric...
I really had given up long time to understand MB 's air cond settings.
The "auto air cond" on my W210 was similar to the C55 in a way that it is "not cold enough" unless the weather outside is real hot.
I found the auto gets confused when the temperature is kind of "in between"; say 22c , that neither give warm air , nor it is cold enough.
I am sure ppl in cold countries will find the opposite - i.e. "not warm enough"
The hint is don't trust the reading on the LCD.
Let's get used to not using the "auto climate".
Senior Member
Joined: Jan 2003
Posts: 367
Likes: 0
From: car in front of you
1998 Silver C43
Originally Posted by EKaru
Sometimes when I drive I have the windows partly down with the heat on... What I find annoying is when the heat is on max it's blowing hot air (as it should), but when I move the knob one click lower the air is cool (even though it's still clearly in the 80s range).... The C32 also had the same problem, but I never encountered this issue on other climate controlled cars...
Eric...
Eric...
Same thing happens in my C43.
