Car heaters are designed to keep the interior of a vehicle warm in colder weather. Most car heaters work by circulating heated air through the vehicle cabin through a fan-driven motor. The air is then directed into the vehicle through a variety of vents. The motor also controls the temperature of the cabin.

Depending on the type of heater, the heater may be hardwired directly into the car's battery or use an inverter. This can drain the battery when the car is stationary. A timer may help you save money on electricity when you have less cold weather. Generally, car heaters use two to four hours to warm the engine.

If you find your car heater is not producing adequate heat, the most common problem could be low coolant level. To check the coolant level in your car, unscrew the radiator cap and look at the neck of your radiator. If you notice a low coolant level, top off the radiator with a 50/50 mixture of anti-freeze and distilled water. Be careful not to overfill the coolant reservoir.

Another possible problem with your car heaters is the thermostat. This temperature-sensitive valve is located in the cooling system between the radiator and engine. An engine needs a specific temperature to operate at maximum efficiency, and operating below this level will cause the engine to run inefficiently. This will cause more emissions and will cause your car to stop working as effectively.