General description of the cooling system (Mercedes-Benz C-Class W203)

Until the engine is warmed up, the coolant circulates only in the cylinder head and block and in the heat exchanger of the interior heater. As the coolant temperature increases, the thermostat opens the large cooling circuit. The coolant is directed through the radiator by a constantly running pump. The liquid passes through the radiator from top to bottom and is cooled by the air passing through it.

Heater and ventilation

The heater consists of fans and heat exchangers located in the front and rear sections of the passenger compartment. Hot coolant passes through the heat exchangers. When the heater control handle located on the control panel is moved, the valves open and hot air begins to flow into the vehicle's passenger compartment. If you turn on the heater fan, air will be forced into the passenger compartment.

The intake air passes through a filter before entering the passenger compartment (refer to Chapter Routine maintenance). The bulk of dust particles will settle in the filter. It is necessary to observe the frequency of filter replacement. A filter clogged with dust will limit the air supply to the cabin, which will lead to stagnation of air inside the cabin.

Distribution of air flows of the ventilation system is carried out using dampers. An air circulation mode is provided. The dampers are controlled by servo drives.

[Original can be found on the website MercedesMAN]