Why Is My Car AC Blowing Hot Air? (Causes & Solutions)

by Joshua Thomas

Warm and sunny weather is ideal for a daily commute than winter. It is the period when the car interior temperature can hit 140oC and more. The condition can be a little uncomfortable for you and your passengers.

But a well-functioning air conditioner can be a real gem since it blows cool refreshing air to create maximum comfort. The ice-breeze creates a small heaven driving experience during a warm and sunny day.

A malfunctioning air conditioner can spoil your summer fun. It results in a hellish driving experience due to the heat buildup in the car. It is an indicator that your AC needs repair or replacement. There are a couple of reasons why your car AC is not blowing cold air.

So, why is my car AC blowing hot air? It could be due to a faulty condenser, broken compressor, electrical system problems, leaking refrigerant, cooling fans issues, and clogged air cabin filters. But you can fix these AC problems without hiring a professional mechanic.

This article explains the common causes of a malfunctioning car air conditioner. Take the time to read through and learn how to fix a car AC not blowing cold air.

Why Is My Car AC Blowing Hot Air? (Causes & Solutions)
Why Is My Car AC Blowing Hot Air? (Causes & Solutions)

Common Causes of a Car AC Not Blowing Cold Air

Leaking Refrigerant

The most common cause of a car air conditioner blowing hot air sometimes is due to a refrigerant leak. A refrigerant is a liquid that circulates into the air conditioner system by expanding and contracting to eliminate heat in the cabin.

Low refrigerant level due to leaking makes it challenging to get rid of excess heat. The hot air is blown through the AC system into the passenger's compartments. It results in a hellish driving experience during your daily commute.

Airtight car AC systems do not need recharge or top of the refrigerant. The air conditioner system has limited space for the refrigerant to escape and evaporate. But a leaking system happens to be the primary source of heat buildup in the car.

However, locating the exact leaking point can be challenging. The leak usually turns into a gaseous state once it reaches an area of low pressure. The best option is to hire a professional mechanic to help in fixing the problem.

Keep in mind that fixing a car AC blowing hot air costs depend on many factors. Leaking from a hose stem is relatively affordable than a severe leaking issue.

You can also consider fixing small leaks with AC leak sealers. Choose a leak sealer that flows through the system to form a solid substance that helps to block the leak. Follow the product instructions while applying.

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Broken Condenser

The condenser helps in removing heat from the liquid refrigerant before expelling it out. A malfunctioning condenser makes your car AC blow hot air.

The condenser is right in the front grille. The location makes the instrument to be susceptible to getting clog by road debris. A blocked condenser is unable to execute its function.

Hot air from the liquid refrigerant will remain hot. Therefore, the AC will circulate hot air in the passenger cabin and create an uncomfortable environment.

A broken condenser due to puncture in the tubes fosters refrigerant leaking. The leaks make it hard to remove heat from the refrigerant. Hence, it enhances hot air circulation in the car.

Hire a professional technician to help in flushing out a blocked system. Replace the broken condenser to resolve the issue for good. You cannot repair a broken condenser.

Electrical System Problems

Electrical system issue is yet another common cause of a car AC not blowing cold air. But identifying the exact wiring problem can be challenging. Dismantling the entire system will be the best option to track down the issue.

Car air conditioners rely on electric current to function. Proper flow of current enhances the functionality of the components.

Handling the electrical system of your air conditioner without much experience and skills will result in more problems. It would be best to hire an experienced professional to fix the problem.

Faulty Cooling Fans

The condenser has cooling fans that help to remove heat from the liquid refrigerant. Faulty cooling fans make the entire AC system malfunction.

Cooling fans may stop working due to issues with the electrical system and blown out fuse. The fans are also susceptible to being clogged by road debris, and this reduces their functionality.

Replacement of the faulty cooling fans is the best option. The cost of new cooling fans and fixing usually vary depending on the car mechanic's garage.

Faulty Compressor

The compressor is a component that drives the refrigerant in a series of tubes, horses, and interconnected devices. The absence of a compressor makes it impossible for the circulation of the refrigerant.

The air circulated through the AC vents of the passenger compartment will be due to the fans. But expect the air to be hot. The car interior environment will be uncomfortable during a sunny ride.

Failure to use the compressor for an extended period might be possible. Starting the component shock the entire AC system and increase the rate of depreciation.

It would be best to run your compressor for 10-15 minutes a month. The routine should be considered regardless of the current weather condition.

Faulty Expansion Valve

A faulty expansion valve makes your car AC system experience a continuous change of hot and cold air. The sole purpose of the expansion valve is to distribute the refrigerator to the evaporator.

Clogged valve results in obstruction of refrigerant flow. It makes the expansion valve experience frost formation from the exterior end.

The air blown on the expansive valve will be cold while that blown in the car will be warm. If you notice a continuous switch of hot and cold air, it could be due to a bad expansion valve.

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In Conclusion

Understanding the AC system of your car is quite important. It will help regulate your car's air condition during winter and summer.

But there are instances where your car AC will be blowing hot air in summer. So, you may be left wondering why is my car blowing hot air out of the vents.

The common causes of car AC not blowing cold air are the faulty compressor, broken cooling fans, refrigerant leaking, faulty condenser, and expansion valve.

It would be best to hire a professional mechanic to help in fixing the problem. The car AC blowing hot air cost tends to vary from one region to another. Smart Point Garage Florida will help you fix the problem at an affordable cost.

More Sources and References

About Joshua Thomas

Joshua Thomas just simply loves cars and willing to work on them whenever there's chance... sometimes for free.

He started CarCareTotal back in 2017 from the advices of total strangers who witnessed his amazing skills in car repairs here and there.

His goal with this creation is to help car owners better learn how to maintain and repair their cars; as such, the site would cover alot of areas: troubleshooting, product recommendations, tips & tricks.

Joshua received Bachelor of Science in Mechanical Engineering at San Diego State University.

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