Why My Car Ac Blowing Hot Air After Recharge?

Nothing beats a cold air conditioner on a hot California summer day. But air conditioner problems can be a real pain for car owners. Sometimes it happens that even after servicing and recharging the whole AC system, the car ac blowing hot air after recharge through the vents.

It can be really frustrating to find out the real cause for the problem, but the air conditioner system is not that complex and it can be diagnosed fairly easily.

What Causes Car Ac Blowing Hot Air After Recharge?

The reason for car AC blowing hot air after recharge can be many. An air conditioner system is a closed-loop system, which relies on several conditions in order to work in a perfect manner. Although the air conditioner system is fairly simple, if the essential elements are out of order then it would not work perfectly. The reasons can be summarised as follow-

1. Low Gas Charge 

Sometimes it happens that even after servicing the air conditioning system, the system is not charged according to the required amount of refrigerant. It can be a mistake due to a faulty servicing machine or the mechanic not being familiar with the requirement of the car’s air conditioning system. A low charge will not create enough pressure in the system, leading to below-average performance. 

2. Clogged Heat Exchangers

An air conditioner system has two primary heat exchangers in the system i.e the condenser and evaporator. In order to work properly, both the heat exchangers need to be in a perfectly clean state so that the air could properly absorb the heat from the cores. If they are blocked with dirt or dust then a proper heat exchange would not be possible leading to a higher running pressure in the system. It can eventually damage the compressor. 

3. Failing Compressor


The compressor is like the heart of the whole air conditioning system and as any component of the car, it has an infinite amount of life. They can give up after serving for the required amount of time and a failing compressor can lead to poor air conditioning performance. The air conditioning compressor is usually made out of machined parts, but poor maintenance can cause them to fail prematurely.

4. Bad Expansion Valve

In reality, the expansion valve really controls the whole and conditioning system, it decides how much refrigerant should flow in the system in order to provide optimum cooling performance. It so happens that sometimes, due to wear and tear the ac expansion valve gets stuck in one position and as a result, proper flow of refrigerant is not maintained leading to poor ac performance.

What Are The Symptoms Of Poor Ac Performance?

For once the air conditioner system will not be able to maintain an optimum cabin temperature due to poor performance. It could also happen that the air conditioner system only works during the early morning or evening time. If the refrigerant is low or the car is he would not work at all. Also, a failing compressor can sometimes work and sometimes fail to works in an intermediate way. 

How To Fix Car Ac System?

Fixing a car ac blowing hot air is an easy job. Since it involves fairly low components, diagnosing and fixing it is easy. Here are major ways to fix the car ac blowing hot air after recharge system-

1. Compressor Repair

A week car ac compressor can lead to poor ac performance. The good news is that the compressor is generally made out of robust materials and they can be easily repaired as they have many child parts. Generally, the gaskets and seals are the main culprits for the poor performance. But it so happens sometimes that due to lack of lubrication or due to poor maintenance of the car ac system the compressor can seize prematurely during the life cycle and leading to failure.

Depending on the brand of compressor, they can do sometimes be repaired, or sometimes the cost of repairing is high as compared to replacement. So in that case, going for a new compressor is the best option. The new compressor, if it has been seized before, should be replaced along with the condenser as it might catch the metallic particles from the old compressor and it can lead to failure of the new compressor as well.

2. Properly Recharging Ac System

It can be possible that last time the car system was not properly recharged by the mechanic and as a result of insufficient refrigerant in the system, the ac is not working properly. To fix that, the car ac system should be evacuated properly, and then it should be recharged according to the required amount of refrigerant. It must be noted that a proper amount of refrigerant oil must also be added.

3. Cleaning Heat Exchangers

The car ac heat exchangers that are the condenser and evaporator core must be cleaned thoroughly in order to eliminate any dust or dirt from the cores. Washing or cleaning them is a simple process but cleaning the evaporator core, which sits inside the dashboard can be a very labor-intensive process.

4. Replace Expansion Valve

Replacing the expansion valve is also a simple process as it can be easily accessed through the firewall of the car. It must be noted that before installing the new extension, the O rings must be replaced and they must be properly lubricated before installing. 

How Much Will An AC System Repair Cost?

Repairing a warm air conditioner can cost a wide range of scales. If it only requires a cleaning job then it can be done within 100 dollars but if any major component needs to be replaced like a compressor then the cost can go up to $500. 


In the end, it can be concluded that fixing a car blowing warm air after recharge is a fairly simple process and can be done at any car AC shop. If any major component needs to be replaced then it can be a very labor-intensive process and can cause a wide hole in your pocket. But if regular maintenance is followed then these scenarios can be avoided.

If you still have any queries regarding this then you can comment down below.

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