Automatic heater and air conditioner, ventilation in Mercedes-Benz W203

Automated heating system (Heizmatic) 
1 - Control panel 
2 - Air supply adjusting wheel for left middle vent 
3 - Rotatable middle vent, left 
4 - Cold air mixing adjusting wheel for middle vents, side vents and air vent on instrument panel, top and middle vents in the rear (on models with automated Thermatic or Thermotronic HF) 
5 - Rotatable middle vent, right 
6 - Air supply adjustment wheel for the right middle vent 
7 - Ventilation deflector on the instrument panel, from above, with air supply adjustment wheel 
8 - Adjusting wheel for side vent air supply 
9 - Rotatable side vent 
10 - Side window defrost vent 

Control panel 

1 - Rotary air supply switch 
2 - Temperature control for left side 
3 - Temperature control for right side 
4 - Air distribution control 
5 - Window defrost 
6 - Switch to air circulation mode, engine residual heat mode on suitably equipped models 
7 - Rear window heater.

The set temperature is reached in heating mode as quickly as possible and kept constant. The temperature can be set for each side separately. 

Change the set temperature only in small increments. 
Models with the function of using the residual heat of the engine: 

When using the "Residual engine heat mode" function, the vehicle interior can also be heated when the engine is switched off. 
We recommend setting the thermostats to 22°C as a basic setting for interior temperature control. 
General notes on automated heating system The 
dust filter completely retains pollen and dust particles up to a certain value. 

If the passenger compartment is heated by the sun, air it out quickly before driving.

Manual air distribution control Air 

distribution control is carried out simultaneously for the left and right sides. 

 Air outlet at the top from the middle and side vents, as well as from the vents on the instrument panel. 

 Air outlet from windshield vents and side window defrost vents. 

 Air outlet from footwell vents, center and side vents and rear footwell vents. 

Basic position of the controls in heating mode (in winter) 
Set the temperature controllers (2 and 3) as desired. 
Set the air supply regulator as desired, but not less than position 2, otherwise the windows may fog up. 
Install the air distribution regulator (4) as shown in the illustration above. 
To reduce the temperature in the space under the ceiling, open the adjusting wheel for mixing cold air as desired. 

Open the middle and side vents as desired. 
Basic position of the controls in ventilation mode (summer) 
Set the temperature controllers (2 and 3) as desired. 
Set the air supply regulator (1) as desired, but not less than position 1. 
Turn the air distribution regulator (4) to  . 

Open the middle deflectors. 
Open the side deflectors.  

In order to evenly distribute air, open the ventilation deflector on the top of the instrument panel. 

With this installation, good ventilation of the cabin is ensured. 
Special positions - select only for a short time 
Switching off and on the automatic heating system 
Turn the air supply rotary switch to 0. 
To switch on the automatic heating system, turn the air supply rotary switch to the desired fan position. 

Defrosting windows 

Press the button  . The control LED on the button lights up. 

If necessary, switch off the air circulation mode  . The control LED on the button goes out. 

Windows fogging up from the inside 

Switch off the air circulation mode if necessary (6). The control LED on the button goes out. 

Turn the air distribution regulator (4) to position  . 

Set the air supply regulator (1) to a higher fan stage.

Set the temperature controllers (2 and 3) to a higher temperature. 

Windshield fogging from the outside \
Turn on the wiper. 

Close the air vent on the top of the instrument panel. 

Turn the air distribution regulator to position   or  . 

Penetration of unpleasant odors from the outside into the passenger compartment 

Switch on the air circulation mode only for a short time, otherwise the windows may fog up. 

Turn on the air circulation mode: press the button . The control LED on the button lights up. 

The air circulation mode will automatically turn off after about 5 minutes.  

Residual engine heat mode 

When the engine is switched off, interior heating is still possible for some time. The duration of heating depends on the set temperature. 

Set both temperature controls as desired. 
Set the air distribution through the ventilation deflectors as desired.

Before switching on: turn the key in the ignition switch to position 1 or 0 or remove it. 

Switching on the mode of using the residual heat of the engine 

Press the button  . The control LED on the button lights up. 

Switching on is not possible if the battery is not sufficiently charged. 

Switching off the engine residual heat mode 

Press the button  . 

The control LED does not go out. 

Automatic switch-off takes place: 

· if the ignition key is turned to position 2, 
· after approx. 30 minutes, 
· if the battery voltage drops. 

Automated air conditioner (Thermatic) 

The location of the controls and deflectors is shown in the illustration at the beginning of the Section. 
Deflectors in the rear

1 Rotatable rear center vent, left 
2 Adjusting wheel for rear center 
vents Opening: Turn the adjusting wheel upwards. 
3 Swiveling center vent in the rear, on the right

Control Panel

1 Rotary air supply switch 
2 Temperature control for left side 
3 Temperature control for right side 
4 Air distribution control 
5 Rear window defroster.
6 ECO mode (no cooling), engine residual heat mode 
7 Automatic air distribution and fan  speed control
8 Air circulation mode button 
9 Window defrost 

The automatic air conditioner is only operational when the engine is running. If ECO mode is selected   , the cooling system does not work. 

In automatic mode, the automated air conditioner performs cooling or heating depending on the outside temperature and the desired temperature in the vehicle interior. When the automatic mode function is off, the air supply and distribution can also be adjusted manually. 

When using the "Residual engine heat mode" function, the vehicle interior can also be heated when the engine is switched off.
The temperature can be set for each side separately. Change the set temperature only in small increments. 

General Notes on Automated Air Conditioner The 
dust filter completely traps pollen and dust particles up to a certain amount. 
If the passenger compartment is heated by the sun, air it out quickly before driving. 
In the storage compartment between the front seats, air conditioning can be carried out in the compartment on the middle console under the armrest console - see below in this Section).

Basic position of controls in automatic mode 

Press the button  . The air supply and distribution are controlled automatically. 

Set the temperature controls to 22°C as the basic setting for interior temperature control. Change the set temperature in small increments. 

Heating mode 

To reduce the temperature in the space under the ceiling, open the adjusting wheel for mixing cold air as desired. 

Cooling mode 

In order to evenly distribute the air, open the ventilation deflector on the top of the instrument panel. 

Special provisions - select only for a short time 

Switching off and on the automated air conditioner 

Rotary air supply switch turn to 0. Automated air conditioner off. 

To turn on the automated air conditioner, turn the air supply rotary switch to the desired fan position. 

Manual regulation of air supply and distribution 

Press the button  . The control LED on the button goes out. 

6 fan stages and air distribution can be selected manually. 

Return to automatic mode: 

Press the button  . The control LED on the button lights up. 

Manual air distribution control: Air 
 
distribution control is carried out simultaneously for the left and right sides. 

 Air outlet at the top from the middle and side vents, as well as from the vents on the instrument panel. 

 Air outlet from windshield vents and side window defrost vents. 

 Air outlet from footwell vents, center and side vents and rear footwell vents.

Defrosting the windows  
Misting the windows from the inside 

Press the button  . The control LED on the button lights up. 

Turn off air circulation mode   . The control LED on the button goes out. 

Fogging of the windshield from the outside 

Turn on the windshield wiper . 

Close the air vent on the top of the instrument panel. 

Manual mode: turn the air distribution control to position   or  . 

Air circulation 

mode Switch on the air circulation mode: 

The control LED on the button   is off. 

Lightly press the button  . The control LED on the button lights up. 

Switching off the air circulation mode: 

The control LED on the button   lights up. Lightly press the button  . The control LED on the button goes out. 

Switching on the air circulation mode and activating comfort closing: 
The control LED on the button   is off. Button  press and hold for more than 2 seconds, the side windows open. The control LED on the button lights up. 

Switching off air circulation mode and activating convenience opening: 
The control LED on the button   lights up. Press  the button  and hold it down for more than 2 seconds, the side windows return to the position they were in before closing. 
 
If, after convenience closing, one of the windows is lowered manually or the glass roof panel is opened, it does not return to the position in which it was before closing during convenience opening. 

Switching from the air circulation mode to the outdoor air supply mode is carried out automatically: 

· after 30 minutes when the outside temperature is above approx. 5°C, 
· after 5 minutes when the outside temperature is below approx. 5°C, 
· after 5 minutes if ECO mode has been selected  . 

At high outside temperatures, automatic switching to air circulation mode takes place. Approximately 30 minutes later, outside air is introduced. 

Economy mode 

Activate economy mode: 

Press the button  . 

The control LED on the button lights up. 

The cooling system is not working and dehumidification is not performed.

Residual engine heat mode 

When the engine is switched off, interior heating is still possible for some time. The duration of heating depends on the set temperature. 

Set both temperature controls as desired. 

Set the air distribution through the ventilation deflectors as desired.

Before switching on: turn the key in the ignition switch to position 1 or 0 or remove it. 

Switching on the residual heat mode of the engine: press the button  . The control LED on the button lights up. 

Switching on is not possible if the battery is not sufficiently charged. 

Switching off the engine residual heat mode: 

Press the button  . 

The control LED on the button goes out. 

Automatic switch-off takes place: 
· if the ignition key is turned to position 2, 
· after approx. 30 minutes, 
· if the battery voltage drops. 

Automated air conditioner with comfort control (Thermotronic) 
The location of the controls and deflectors is shown in the illustration at the beginning of the section. The rear vents are located similarly to the Thermatic models (see above). 

Display and keyboard

1 Temperature on the left side, decrease 

2 Temperature on the left side, increase 
3 Air distribution on the left side (automatic, manual) 
4 Active carbon filter 
5 Display 
6 Air distribution on the right side (automatic, manual) 
7 Temperature on the right side, increase 
8 Temperature on the right side, decrease 
9 Rear window heater.
10 ECO mode (no cooling), engine residual heat mode 
11 "+" 
pushbutton switch Turn on the automated comfort control air conditioner 
12 Pushbutton air supply switch - 
Turn off the automated comfort control air conditioner 
13 Air circulation button 
14 Window defrost 

Display

1 Temperature on the left side 
2 Temperature on the right side 
3 Fan steps 
4 AUTO function (automatic mode) 

activated The comfort controlled automated air conditioner is only in standby mode when the engine is running. 

In economy mode  , there is no cooling. 

In automatic mode, the automatic air conditioner performs cooling or heating depending on the intensity of the sun, the outside temperature and the desired temperature in the vehicle interior. When using the "Residual engine heat mode" function, the vehicle interior can also be heated or ventilated when the engine is off. 

Change the set temperature only in small steps. The automatic air conditioner can be installed for the left and right sides separately. 

The set temperature is reached as quickly as possible and kept constant. 

General recommendations for an automatic air conditioner 

Refer to the appropriate subsection relating to the Thermatic HF above in this Section. 

Basic position of controls - in automatic mode 

Press both knobs  . The symbols   ,   and are   no longer illuminated. 

The EU economy mode and air recirculation functions are disabled. At the same time, the automatic fan mode is activated. 
We recommend setting the temperature indication on the display to 22°C as a basic setting for interior temperature control. Change the set temperature only in small increments. 

Heating mode 

To reduce the temperature in the space under the ceiling, open the adjusting wheel for mixing cold air as desired. 

Cooling mode 

In order to evenly distribute the air, open the ventilation deflector on the top of the instrument panel. 

Special positions - select only for a short period of time 

Switching off and on the automated air conditioner with comfort control  Press

the air supply rocker switch on the left   until the display goes out. 

To turn on the automated air conditioner with comfort control,  press the air supply rocker switch to the right. 

Manual air control 
7 fan stages can be selected.  

Press the air supply key switch on the right   or   left several times until the required fan stage is set. The fan steps are indicated on the display. 
The indication "AUTO" on the display goes out and the automatic fan mode is turned off. 

To turn on the automatic fan mode, press the left or right   air distribution knob. 

Manual air distribution control 

Press the knob . The handle is pulled out, the symbols   ,   and  are visible . Turn the knob according to the required air distribution. 

 Air outlet from the middle and side vents, vents on the doors and at the windshield. 

 Air outlet from the middle and side, deflectors on the doors and at the windshield. 

 Air outlet from center and side vents, door vents and footwell vents.

Return to automatic mode: Press and lock the knob  . The symbols   ,   and are   no longer visible. 

Defrosting the windows 

Misting the windows from the inside 

Press the button  . The control LED on the button lights up. 

If necessary, switch off the air circulation mode  . The control LED on the button goes out. 

Fogging of the windshield from the outside 

Turn on the windshield wiper . 

Close the air vent on the top of the instrument panel. 

Manual mode: 

Turn the air distribution regulator to position   or  . 

Air 

circulation mode Turn on the air circulation mode: 

The control LED on the button   is off. 

Briefly press the button  . The control LED on the button lights up. 

Switching off the air circulation mode: 

The control LED on the button lights up  . 

Briefly press the button  . The control LED on the button goes out. 

Switching on the air circulation mode and activating comfort closing: 

The control LED on the button is off. 

Press   and hold the button for more than 2 seconds, the side windows and the sliding and lifting sunroof close. The control LED on the button lights up. 

Switching off the air circulation mode and activating comfort opening: 

On the button  control LED is lit. Press  the button  for more than 2 seconds, the side windows and the sliding and lifting sunroof move to the position in which they were before closing. 

If, after convenience closing, a window is lowered manually or a sliding and lifting sunroof is opened, comfort opening does not reach the position they were in before closing. 

Switching between air recirculation mode and outdoor air mode is automatic: 

after 30 minutes if the outdoor temperature is above approx. 5°C, 
after 5 minutes if the outdoor temperature is below approx 
.  . 

At high outside temperatures, automatic switching to air circulation mode takes place. Approximately 30 minutes later, outside air is introduced. 

Economy mode 

Activate economy mode 

Press the button  . 

The control LED on the button lights up. 

The cooling system is not working and dehumidification is not performed.

Activated carbon filter and automatic air circulation, taking into account outdoor air pollution 

The filter significantly reduces the concentration of harmful substances and largely retains odors. 

Automatic switching to the air circulation mode is performed if the concentration of carbon monoxide (CO) or nitrogen oxide (NOx) in the outside air has increased. 

Automatic air circulation mode is not available when ECO mode is selected   or the outdoor temperature is below 5°C.

Activation of the carbon air filter and air circulation, taking into account the pollution of the outside air with exhaust gases: 

The control LED on the button   is off. Briefly press the button  . The control LED on the button lights up.

Switching off the carbon filter for air circulation, taking into account the pollution of the outside air with exhaust gases: 

The control LED on the button lights up  . 

Briefly press the button  . The control LED on the button goes out. 

Switching on the charcoal filter and automatic air circulation and activation of comfort closing: 

The control LED on the button   is off. Press  the button  for more than 2 seconds, the side windows and the sliding and lifting sunroof close. The control LED on the button lights up.

Switching off the charcoal filter and activating convenience opening:  The  control LED

on the button  lights up. Press  the button  for more than 2 seconds, the side windows and the sliding and lifting sunroof move to the position in which they were before closing. 

If, after comfort closing, a window is lowered manually or a sliding and lifting sunroof is opened, comfort opening no longer reaches the position they were in before closing. 

Motor Residual Heat Mode 

Refer to the appropriate subsection for Thermatic HF earlier in this Section. 

Air-conditioned compartment in the center console under the armrest 
(models with automatic air conditioning)

The compartment contains a ventilation deflector . 

Opening: push the handle (1) up. 

Closing: push the handle (1) down. 

The air supply depends on: 

· the set air distribution, 
· the set air supply, 
· the opening position of the air vents on the instrument panel. 

The air temperature approximately corresponds to the temperature of the air leaving the middle vents. It cannot be installed separately.

Source: http://www.auto-knigi.com/model/mb_c/2_12/