BLOWING COOL AIR WHEN WHEN HEATER VENTSWITCHES ON HEAT(C200)

[HSRAM57]

NEW MEMBER ,HELP !
IVE RECENCTLY BOUGHT A C200 ELEGANCE P REG AND HAD A PROBLEM WITH OVER HEATING ,THIS WAS CURED ,BY REPLACNG THE VISCOSE FAN COUPLING BUT WHEN I PUT THE BLOWERS ON ,THE TWO SIDE VENTS BLOW HOT AIR BUT THE FRONT MIDDLE ONE BLOWS COOL AIR .....CAN YOU ADVISE PLEASE....THANKS.

 

[Geoff_Slade]

Hi and welcome to the forum.

If the C class is anything like a W124 E class then that's the way that the ventilation system is set up the two outer vents respond to the heater setting i.e. they blow air at the set temperature whereas the centre ones blow either unheated air or if you've got air con on they'll blow cold air but they won't blow warm or hot air. I assume it's a Merc quirk (stupid if you ask me one side of your body gets warm and the other side either gets cold if you have the vents open or even with them closed it just doesn't warm up which still feels wrong).

Ah well I'm sure the guys at Stuttgart know what they are doing.

There are some diagrams in my manual that explain how it works. I must admit that when I tried the heating on my car just after getting it I thought there was something wrong being used to "normal systems" where all the face level vents are connected to the heating system. All the Japanese cars I've owned have had a system where you can blow hot on your feet and face or cold on your face and hot on your feet; unfortunately the German cars don't seem to have that feature (I've had a couple of VWs in the past).

If you haven't got a manual let me know and I might be able to scan the relevant pages in (although as I say it's an old E class so the fascia setup will look different to yours.

Let me know how you get on.

Cheers

 

[landover]

This is normal the centre does blow cold air.

 

[HSRAM57]

TO GEOFF AND LANDROVER (MEMBERS)

THANK YOU VERY MUCH FOR YOUR HELP ON MY BLOW AIR SYSTEM QUESTION.GOD BLESS YA BOTH.

STEVE.

 

[HSRAM57]

CANT THANK YOU ENOUGH LADS.CHEERS

 

[philster]

Yes, can also confirm that the central vents blow cool air only, regardless of temp setting. My 1994 W202 does exactly the same. Apparently, the reason for this is so that all the hot air is channelled out of the front and side vents, thereby making de-misting/de-frosting the windscreen and side windows as quick as possible. Having some of the hot air channelled through the central vents would mean slower de-misting, and would therefore make the car perform less well in safety/performance tests. Hope this helps.