Updated at: 04-04-2022 - By: micdot

There are a number of reasons why your car’s air conditioner may be blowing hot air. In order to get the issue resolved as quickly as possible, follow this short guide. If you’re looking for an expert on this subject, you’ve come to the right place. More information is available on the about page. Has your car’s air conditioner recently failed you?

There are few things more frustrating than anticipating a crisp breeze only to be greeted by a scorching gust of wind. Why is my car AC spewing hot air? That’s a good question, and you’ve found the answer right here. Refrigerant is the most typical reason of an AC system blowing warm air, but you may also have a condenser problem. Additionally, a malfunctioning compressor, broken cooling fans, or an issue with your electrical system could be at blame for the problem. Fortunately, we’ll go through each of these AC issues in depth in this tutorial. But before we get into the nitty-gritty of how a car’s air conditioning system works, let’s take a closer look at how it works. Let’s get this party underway as soon as possible!

List of Chapters


Your Car’s AC System Explained

How Your Cars AC System Works & How to Diagnose It's Symptoms


In a gaseous condition, the compressor compresses the low-pressure, low-temperature refrigerant into a high-pressure, high-temperature gas.


The condenser is like a small radiator for the cooling system. High-pressure, hot gas from the compressor flows into the heat exchanger. A high-pressure, lower-temperature liquid is formed when the refrigerant condenses. The condenser is cooled by a pair of cooling fans as well. As long as the refrigerant is in the lines, it will lose a lot of its heat this way.


Now that the refrigerant is liquid, the receiver/dryer is in responsibility of eliminating the moisture. Desiccants, a chemical that absorbs moisture, are used to filter the water. In the past, you may have come across a small packet in a bottle of medication or a new pair of shoes. To avoid freezing and clogging of the expansion valve, it is necessary to eliminate moisture from the refrigerant. In contrast to water’s freezing point of -32 degrees, the freezing point of refrigerant can be as low as -200 degrees.

Expansion Valve/Orifice Tube

The nozzle on a hose is analogous to an expansion valve in that it regulates the flow of coolant through the system. In addition to lowering pressure and heat, the expansion valve causes it to expand. Not only that, but the gaseous state is returned to a lower temperature and lower pressure. Instead of an expansion valve, some systems have an orifice tube. In terms of function, they are nearly identical, but the evaporator temperature can be used to control the size of the aperture. The receiver/dryer is omitted in favor of an accumulator, which functions in a manner similar to that of a rechargeable battery.


The refrigerant travels through the evaporator’s internal lines, making it similar to a radiator in operation. When it’s in these lines, the heat is absorbed and dissipated, lowering the temperature to around 32 degrees Celsius. It’s an oddity of coolant that, unlike water, it boils before it freezes. In addition to cooling the temperature, this process results in the gas returning to its original state. Afterward, a fan blasts chilly air into your cabin through the evaporator. Finally, as a coolant gas, the coolant returns to the compressor and begins the process all over.

5 Reasons Your AC Is Blowing Hot Air And How To Fix Them

AC Blowing Hot Air: What's Wrong? 6 Common Causes & Fixes For AC Warm Air

Your Car Is Leaking Refrigerant

Recharging refrigerant is only necessary if there is a leak in the system, which is quite unlikely because refrigerant is constantly regenerated. There’s a leak if your air conditioner begins to pump warm air. Unfortunately, pinpointing the source of the leak can be a challenge. Why? Because it changes back into a gaseous condition when it comes into contact with an area of low pressure, like a leak. When it comes to repairing an AC leak, you have two choices.

The first step is to take it to a shop so that the leak can be found and any damage or worn parts can be repaired or replaced. This can cost anything from $225 to $1,600, depending on the severity of the problem. Expect the leak to be smaller if the hose is worn than if the compressor needs to be replaced. While an AC leak sealer is another alternative, keep in mind that these devices are designed for smaller leaks. Weed sealers come in two varieties. Seals enlarge as a result of the first type of treatment. To assist stop a leak, the second type is designed to flow through the system until it reaches the source of the leak and then solidify. Between $25 and $50 will get you a canister of each. The nozzle on the majority of these devices is designed to be used with a high-pressure port. Keep in mind that the product’s instructions must be followed exactly.

The Condenser Is Malfunctioning

The condenser, as you may recall, is responsible for extracting heat from the refrigerant and then releasing it into the atmosphere. Because of a malfunction, your car’s air conditioning will be swelteringly hot. Because the condenser is located beneath the front grille, road debris may have blocked or punctured one of the internal lines.

A blockage can be removed, but it’s usually impossible to fix it, so you’ll have to buy a whole new device instead. According to the make and model of your vehicle, replacing a condenser might cost anywhere from $450 to $950.

Issues In The Electrical System

An electrical problem should be the last thing on your mind if your air conditioner is blowing hot air. Why? Because many of the cables in the system are hidden from view, finding the problem can be difficult. Since many of the AC’s components require energy to work, your air conditioner may blow heated if you don’t supply it. While electrical tape may be able to repair any frayed or damaged wires, you’re better off taking it to a qualified specialist for further assistance.

Problems With The Cooling Fans

As previously mentioned, the condenser features two cooling fans that help cool the refrigerant as it travels through the lines of the unit. The AC system will not function properly if any of these are defective or malfunctioning. There are a number of possible causes, including a blown fuse or a problem with the electrical system. Because they’re so close to the front of the vehicle, they’re vulnerable to harm by flying road debris. The only other choice is to replace the item. Replace them and you’re looking at a budget of $300-$500.

Radiator Fan Is Not Working? (7 Causes & How To Fix)

The Compressor Is Faulty

The compressor is where it all begins, and as you might expect, if it malfunctions, the entire system will as well. Why? Because it is the compressor that initiates the movement of the refrigerant. What causes compressor failure in air conditioning systems? Lack of use is one of the most prominent contributing factors in many cases. When you turn on your air conditioner after a long period of inactivity, it can cause it to wear out more quickly than normal. Running it for around 15 minutes every few weeks is a good idea because of this. The compressor has a lot of moving parts, which makes it virtually preferable to replace it rather than repair it.. Unfortunately, you’ll have to fork over between $500 and $700 for a new one. By utilizing your AC compressor more regularly, you’ll be able to extend its lifespan.

Why Does Your Car AC Blow Hot Air?

That’s because there’s an internal problem that needs your attention. As a reward for your perseverance, you now have a much clearer picture of the problem. The longer you wait to fix the problem, the more probable it is that it will get worse. Is it possible to live without air conditioning in a hot climate?

Not worth the effort.