Why Is My A/C Blowing Hot Air In My Car? 6 Reasons Why

To make our journey comfortable and pleasant in the car we usually use air conditioning and depending on the weather we will regulate the temperature to hot or cold. These are the gadgets that if it doesn’t work it can make a car journey really unpleasant and in some cases even dangerous.

What can we do if one day the air conditioning system is just blowing hot air in our car? Your question, why is my A/C blowing hot air in my car will be answered in this post. Here we will explain what causes the car not to blow cold air and also how we can fix the problem.


The air conditioning system is designed to prevent our vehicle from overheating. To do this, the engine of our car has a series of pipes that goes from the interior of the car to the radiator. The cooled liquid flows through this circuit. The hot fluid flows from the engine to the radiator, where it is cooled by the incoming airflow due to the speed of the car.

Once cooled, the fluid flows back into the engine, regulating its temperature. The coolant liquid, although it seems cold, is at about 90 degrees Celsius. Our car’s heater works by taking advantage of this hot liquid.

Coolant gauge on the dashboard.

To do this, it directs through another circuit to the radiator and uses a fan to blow it into the car and create the desired heat. Did you know that the heat from the engine is used to warm you up? So if we can’t get the cold air conditioning to work, this means that one of the components of the refrigerant circuit is probably broken.

The air conditioning system is composed of a compressor, and pipes that transport the gas, a condenser, the air-conditioned box, and the gas or coolant liquid that the car uses to blow hot or cold air into the car. If any of these components fail or are missing, hot air will be blown into the car and the air conditioning for cold air will not work.

Usually, if any of the components of the air conditioning system fail, we will probably have to take it to a workshop. The repairs on the air conditioning system can be quite expensive so before taking it to repair be prepared that the quote you will be given to you will not be cheap.

Reasons for A/C blowing Hot Air

Below you will find each component that belongs to the air conditioning system and you will see what problems they can cause when they are defective. Here you will be able to answer your question; “Why is my A/C blowing hot air in my car?”

1. Compressor or Pipes Leaking

One of the most common issues is when we want cold air and just get hot air blown into our car, is that the compressor has failed or the pipes are leaking gas. If it’s the compressor, the only solution is to buy a new part. This part can be quite expensive but we can also look for a second-hand part which will be cheaper.

Air conditioning car compressor of an engine disassembled.

If the pipes are leaking, then we must check where the leak is coming from and change the pipe. This is something we can repair if we understand a little about mechanics and if the leak is very small. It also depends on if we have easy access to the pipe or not. If this is not the case we have to take the car to a workshop and the mechanic will have to replace the pipes.

2. Condenser Fails

This part is located at the front of the car and it could be damaged after having an accident or just by hitting it when we are parking or going over speed bumps. Sometimes after accidents when the car is repaired, the fitters don’t notice that there is more damage than just the chassis.

If we go over speed bumps quickly this could also cause the condenser to break. To solve the problem we must buy a new part and have a workshop replace it as it’s a complicated job. Without the necessary tools, it would be very hard to change.

3. Improper Maintenance of the Filter

Another reason that our car is blowing hot air when we want cold air is that the air filter has not been changed and could be clogged up with dust or dirt. This is very common when we don’t have the maintenance done to our car regularly.

Replacing the pollen air filter.

This filter as well as others must be changed every year or every so many mile. This can be different for each car and also each brand. The best way to know is to talk with your workshop which usually takes care of the maintenance and repairs of your car.

4. The Gas Circuit is Leaking

If we feel that we have cold air and in just a few days or months all of a sudden we have just had hot air blown into our car, it’s probably because the gas is leaking. If the leak is quite big, we can look and check to see stains of oil or dirt.

If the leak is small, we would have to use a special liquid to detect the leak. Either way, if we do not have special tools the solution is to take it to the workshop and the fitters will replace the pipe that has been damaged or deteriorated.

5. Air Conditioner Box Failure

If it is not one of the previous failures, the problem may be in the air conditioner box. This box is found next to the fans, if the box doesn’t close probably for whatever reason, both hot and cold air will mix and we will just have hot air conditioning blowing in our car.

If this part is broken then the only solution we have is to replace it. It is an expensive part and as I mentioned earlier we can also ask our workshop if they can replace it with a second-hand part

6. Blown Fuse

The last problem could be very simple and that is a fuse that has blown and could cause your air conditioner to stop working. To solve the problem make sure the rest of the lights and other functions of the car work and take it to the workshop. The mechanics will be able to find the blown fuse quickly and replace it for you. This is usually the cheapest fault to repair.

Mechanic checking car fuses.

Proper Maintenance

Now we know what can be the cause of our car blowing hot air conditioning. As you can see there can be various problems with the air conditioning circuit when no cold air comes out.

The best way to keep our car’s air conditioning working is to keep good maintenance on the coolant liquid and also on the filters, this means regularly checking the level of the coolant liquid, something we can do easily and make sure we go to the workshop and change the filters on time.

Also when driving, make sure we don’t take the speed bumps too quickly if not, we can also break the condenser and this is quite an expensive part to change.

When summer arrives, we can take our car for revision and make sure the air conditioning works well as if it doesn’t and we suddenly have to travel a long distance on a hot day. Without air conditioning, the car trip can turn out to be really terrible.

💡 Did you know that it is very common to fall asleep while driving if you feel hot and tired? It is very important to have a desired temperature in the car, if not it can be dangerous.


If you have any questions or doubts, you can write a comment and we will be more than happy to help you solve your questions on why your car is blowing hot air. Also if you have any other ideas or think of any other way a car might be blowing hot air in our car we would like to know, comment us and we can also help others.

Overall, having hot and cold air conditioning in our car is one of the best ways to have a comfortable, safe, and pleasant journey. Without it, the car trip isn’t so much fun and also very loud as on hot days we would keep our windows open.

When we have young kids, having our air conditioning working well is very important as a very cold day or a very hot day can make a young child feel very sick and air conditioning prevents the car from having extreme temperatures.

These extreme temperatures won’t make an adult ill but on very hot days it can make a driver drowsy and the possibility of the driver falling asleep rises and so this could be a huge problem.

Keeping good maintenance on the car, in general, is what will save your air conditioning system from breaking with short notice.

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About Brock Rangel

Hi, I am Brock, and I am the lead editor/photographer for TheCarColony. I have been a mechanic for over 14 years now, and I am here to spread my car knowledge across the web!

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