One fine day, when winter arrives, the air in the car that should go out hot to the passenger compartment, comes out cold. Horror! In addition to the problems that can be caused by not demisting the windshield, if the interior temperature does not rise to a comfortable level, we will have to bundle up, but this is a bad solution, especially for the driver, who will not be able to drive the vehicle efficiently. But why does cold air come out if I have the car heater on?
Why does the car heater not heat up?
It pays to have a little patience when it is cold, because the vehicle takes longer to generate heat once the car heater is on. There are cars that take longer than others to reach the necessary temperature. But if after a while you do not perceive an improvement in the interior temperature, there is a problem that can have different origins:
- Various causes:  The entry of heat into the interior of the vehicle is produced thanks to the operation of a set of elements. Therefore, it may be one or more of these elements that cause a malfunction of the system , which ends up causing cold air in winter or heat in summer.
- Common faults:  The most frequent causes of heating malfunctions are usually the failure of the thermostat , that of the electric water pump or the internal clogging of a water hose or a solenoid valve .
- . ..And if it is not a heating problem?:  It does not have to be an error in the heating or air conditioning system itself that causes a lack of heat. The failure of some engine component that does not allow it to reach the proper working temperature may be the one that generates the problem.
How does the heating work?
You have probably never asked yourself, but you may be interested to know. When the car’s engine is running, it generates heat, and the radiator (supported by the fan) is responsible for ensuring that excess temperature is not a problem ; Well, that surplus is the one that is used to heat the passenger compartment . But there are different heating systems:
- Mechanics . They are the oldest. They work thanks to a small radiator mounted behind the dashboard that is connected by two hoses to the engine cooling system . In many cases, it incorporates a tap that opens or closes the flow of water to this interior radiator.
Two other fundamental parts of the circuit are the flaps that channel the air inside the heater with the help of the fan, which forces air circulation. To request heat, manually open the tap (if it is included) or the ducting hatch and direct the air towards the desired outlet. If we want more sensation of heat, we start the electric fan that is located in front of the radiator at the desired speed. - Automatic. They are the most modern and are also very varied. The way of obtaining heat and its operation (with exceptions such as electric vehicles) is similar to that of the old systems, but with a fundamental difference: all actions are carried out automatically, selecting (in auto mode) only the temperature that we wish In these conditions, an electronic module controlled by a microprocessor  checks the climatic conditions inside and outside the vehicle and, depending on them, adapts the elements to achieve the comfort values ​​that we have requested.
- Electric heaters . A major change in heating systems is that many use electric heaters to get heat quickly without having to wait for the engine to warm up.