Heater and air conditioner (VW Golf 5)

The interior is heated by air sucked in from outside. Outside air is drawn in by an electric fan and passes through a dust filter (air purifier) before entering the salon.

The air for heating the passenger compartment is heated by a heater or air conditioner.

Hot coolant constantly passes through the heater radiator, which quickly heats up the air supplied to the passenger compartment. Air is supplied to the passenger compartment by a fan operating at different intensities (speeds) (see illustration 8.0).





If, for example, due to pollution of the outside air it is necessary to switch off its intake, then the air recirculation mode can be maintained in the car's interior, i.e. only the air in the interior will be used. To do this, the recirculation mode is switched on by the corresponding button. When the button is pressed, the recirculation mode actuator is switched on.

In Golf/Touran vehicles with a diesel engine, the air for heating the interior is heated more slowly. Therefore, a coolant heating unit with a positive temperature coefficient is built into the coolant circulation circuit. This heater additionally heats the coolant at low air temperatures. After starting the engine, the heater quickly heats the air in the heater depending on the air temperature.

If any faults or malfunctions occur in the heating or air conditioning system, they are registered by the self-diagnosis system and can be read using a diagnostic tester.

Attention! If, as part of the work on the heater, it is necessary to perform actions concerning the electrical system, it is mandatory to disconnect the terminal of the ground wire (-) from the negative pole of the battery. Even the simple disconnection of a wire or connecting terminal is considered work with electrical equipment.

Cars with air conditioning

Golf/Touran cars can be additionally equipped with an air conditioner, which serves both as a heater and as an air conditioning system.

In air conditioning mode, the air conditioner operates on the principle of a refrigerator.


The compressor compresses gaseous, environmentally friendly and ozone-depleting layer-free freon refrigerant R-134A.

As a result, the refrigerant heats up and enters the cooler, where it is cooled and liquefied. Through the pressure reducing valve, the refrigerant is fed to the evaporator, where the resulting liquid again passes into a gaseous state. In this case, it is strongly cooled.

As a result of the evaporation process and the transition of the refrigerant into a liquid state, the air taken from outside is cooled, and the moisture contained in the air turns into condensate.

The intensity of air cooling depends on the set temperature and the speed of the interior air blower.

Warning! Do not open the air conditioner refrigerant circulation system. Contact with the coolant on the skin causes frostbite. If the refrigerant comes into contact with the skin, rinse the skin with cold water immediately for at least 15 minutes. The refrigerant is colorless, odorless, and heavier than air. If the refrigerant leaks, people in the area of the floor on which the vehicle is installed or in rooms located below the leak may suffocate.

When the air conditioner is off, the compressor does not work, which reduces fuel consumption.

In addition, in cars with a diesel engine, the additional heater is switched off, which also has a beneficial effect on fuel consumption.

It is recommended to turn on the air conditioner for a while at least once a month and in the cold season, setting the most intensive mode of operation when driving with normal grayness and with a warmed-up engine. This causes the refrigerant to circulate, and the lubricant contained in it to the parts, preventing their porosity or other damage.

Attention! Work on the air conditioner must be performed in a specialized workshop. For this reason, air conditioner repair is not included in this manual.

On request, Golf/Touran cars can be equipped with automatic air conditioning (Climatronic).

The automation ensures that a constant temperature is maintained in the cabin and the air is dried, which prevents the windows from fogging up.

The volume of air supplied to the passenger compartment and its distribution throughout the passenger compartment are also performed automatically, taking into account fluctuations in outside air temperature. When switching to the economical operating mode, the air conditioner is switched off, but the heating of the passenger compartment and its blowing are performed automatically.