Updated at: 07-08-2022 - By: Lucas

When the weather turns cold, the car heater suddenly becomes an indispensable component, one you’ll reach for on nearly every trip. It’s usually a good idea to stay in a warm and cozy cabin throughout the fall and winter months.

In certain cases, the heater may not operate at all or does not warm the cabin at all, especially when the car is idling. This isn’t good for the windows because it makes them susceptible to steaming.

We need to learn about the entire heating system in order to better comprehend the issues and symptoms of the car heater.

All of the heater’s parts must be in good working order in order for it to function correctly. A radiator, a particular device for regulating the flow of the liquid, pipes through which the cooling liquid circulates, and air ducts are all that is required.

A fan is also part of the heating system in the car. If all of the heater’s components are functioning properly, it will heat the room.

Why is the car heater not working properly?

Heat Doesn't Work In Car

  • The heating system will not work properly if air enters it when the coolant is replaced. So be careful when replacing the coolant.

  • Air can enter the heating system if there is damage to the main cylinder block.

  • The thermostat could be jammed in the open position. If you are going fast enough, the heater can not cope with heating, and at low speeds, it warms well, if that’s so, then most likely this is the problem.

  • Also, the heating-cooling system can not work 100% if the radiator of the heater is clogged. This can happen for several reasons. Insects, leaves, and dust get into the radiator. Or sealant may have entered the radiator. There will be a problem if water or poor-quality coolant gets into the heater’s radiator. We will talk in detail in another article about how to wash the heater’s radiator

  • The cabin filter can also lead to failures in heating if it hasn’t been changed for some time, is clogged or filled with dust and debris.

  • A frequent cause is the failure of the fan itself. Bearings or brushes may fail, causing the entire system to malfunction. There may also be problems directly related to electronics.

  • Sometimes, the heating system fails due to damage to the radiator flap. Air may not enter the system, or it may not enter in a sufficient amount. Thus, a poorly working radiator flap and air vents are often the cause of the poor performance of the heater.

  • A broken heater pipe. In very rare cases, depending on the car model, due to its location in the car, it is very easy to accidentally hit this pipe. It breaks down and is completely unusable. It should be replaced with a new one, after which the operation of the stove should be normalized.

  • A bad or failing heater control unit, the heater controller, could have failed. This will be noticeable if the fan does not work well in positions 1 and 2 or does not turn on at all. Replacing the heater control unit is not so expensive, but most of the time you will have to replace the entire control unit.

  • A faulty air temperature sensor may cause the heating system to malfunction.

You can avoid a lot of money in repairs if you check the above issues at an early stage.

How to maintain the car heater?

Heat Doesn't Work In Car-2

  • It is necessary to regularly clean the radiators to prevent various types of problems. The external radiator can be cleaned with compressed air streams and, if necessary, can be removed and washed under running water. The internal radiator can also be cleaned with a vacuum cleaner if the level of contamination is not very high.

  • When using an aftermarket or just not quite high-quality coolant, build-ups inside the channels of the pipes cannot be avoided. You can easily clean the radiator without removing it. You just need to swap the top and bottom pipes and let the car run a little. You can also clean it with household citric acid or use a special flushing liquid. To avoid this problem, it is recommended to change the coolant at least once every two years.

  • A faulty thermostat must be replaced as soon as possible. In fact, I would not recommend at all driving with a bad thermostat. If it is stuck open, then the heater will not be able to fully warm up the cabin, and the engine itself will take longer to warm up. If the thermostat is stuck open, then this can lead to engine overheating, which means the engine could fail, or it will require high costs for repairs.

  • If the air from the heater is hot, but its flow is very weak, then the cabin filter is most likely clogged. It is not recommended to use a car without a cabin filter, as all dust, microbes, leaves, and debris from the road will get directly into the cabin. Therefore, the filter should be replaced with a new one.

  • The heating system will not work well if there are air bubbles in it. This is not a big problem, it can be solved. First, you should try to expel the air with the engine off. Open the cap of the coolant reservoir, find the hose from the reservoir to the radiator and try to pour antifreeze by hand. If this method is not working, then it is necessary to let the car idle.

  • You also need to pay attention to the control levers of the heater itself. If the cable or heater valve has come off, this may be the reason for the poor operation of the entire system.

  • The bearings on the heater fan should be periodically lubricated, and also cleaned of dust.

At 25 degrees Celsius (13 Fahrenheit), the heater can be deemed pretty serviceable if it warms the cabin up to +16 degrees Celsius (61 F) from the bottom and +10 degrees Celsius (50 F) from the top. If this is the case, the temperature in the back seats of the automobile should be around +15 degrees Celsius (59 F). For both the driver and the passengers, having a perceptible change in cabin temperature between the bottom and the top of the cabin will ensure a pleasant journey.

Preventative actions should be implemented on time and with care to avert such issues. You’ll be able to relax and enjoy the ride in a warm vehicle. Make your journey safer by shielding the windows from the ice or steam. The car’s heating system demands more upkeep the more you use it. All automobiles are affected by this.