A liquid-type interior heater is installed on a Renault Mega 2 car

The Renault Megan 2 heating, air conditioning and ventilation system is a single complex that provides the most comfortable conditions in the car interior, regardless of weather conditions and driving conditions

The system includes a heater (increases the air temperature in any operating mode of the system), an air conditioner (reduces air temperature and humidity), an air blower (fan) and air ducts with a filter (provide air exchange in the cabin, clean the air from dust), as well as control unit (controls all elements of the system to obtain the specified comfort parameters).

The heater radiator is connected to the engine cooling system by two hoses running in the engine compartment.

The radiator is placed in a plastic casing of the climate unit, installed under the central part of the instrument panel.

Scheme of the movement of air flows in the heating system: 1 - windshield vents; 2 - dampers for the distribution of air flows to the windshield deflectors and instrument panel deflectors; 3 — instrument panel deflectors; 4 - air ducts for heating the driver's and passengers' legs; 5 - damper for distributing air flows to the instrument panel deflectors and air ducts for heating the driver's and passengers' feet area; 6 - heater radiator; 7 - cabin air filter; 8 - damper of the air recirculation system; 9 - air intake box; 10— air intake in the passenger compartment; 11 - fan impeller; 12 - fan motor; 13 - air conditioner evaporator; 14 - drainage hole for draining condensate; 15 - damper of the temperature controller; 16 - housing of the heating and air conditioning unit

The main components of the heater:

  • - heat exchanger (radiator) 6 (Fig. 1) of the heater, designed to heat the air entering the cabin with the heat of the engine cooling liquid;
  • — fan (air blower) 11.

Permanent magnet-excited fan motor 12, providing a controlled supply of outside air to the heater and air conditioning dampers.

In order to obtain different values ​​of the fan speed, a block of additional resistors is installed in the power supply circuit of the electric motor;

  • - damper 15 for the temperature regulator of the air coming from the heater to the passenger compartment.

The amount of air passing through the heat exchanger of the heater and the amount of outside air passing through the heat exchanger depends on changing its position;

  • - dampers 2 for distributing air from the heater through air ducts to the passenger compartment or for blowing the windshield.

Heater assembly: 1 - fan electric motor, 2 - pipeline flange, 3 - flange mounting bolt, 4 - heater radiator connection clamp bolt, 5 - heater radiator, 6 - heater radiator mounting screws

Heater assembly in picture 2.

Possible malfunctions of the heater and remedies

Fault - Troubleshooting

Weak performance

The air cover does not close completely - Check the positions of the cables, adjust the operation of the cover, remove foreign objects if necessary

Heat exchanger clogged or piping crushed - Replace heat exchanger, check piping

Cable is broken or has come off - Replace, reattach accordingly

Heat exchanger flow or return blocked or broken - Check and replace hoses if necessary

The heating is turned off while driving

The heat exchanger was idle due to loss of coolant - Watch the temperature gauge.

If it is already in the red sector, stop immediately, otherwise there will be a danger to the cylinder head gasket.

Troubleshoot and add coolant

Faulty cylinder head gasket - Replace gasket

The fan does not work in all modes

Fuse blown - Replace fuse

Fan switch failed - In all positions, check the switch for current flow

Fan Motor Failed - Run an auxiliary wire from the positive battery terminal to the white/brown fan motor wire connector.

If email If the fan motor does not work, the motor is defective and needs to be replaced.

Auxiliary resistor burnt out - Replace additional heater resistor