Car AC Blowing Warm Air Intermittently: What to Do?

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The AC unit is one of the most frequently used parts of your car. But when the ac unit isn’t serving its goal, things become a little uncomfortable for us all.

Sometimes, a car air conditioner blows hot air instead of cold air. And you need to know how to solve the problem immediately.

Well, you might call up a car mechanic and solve such a car ac cooling problem for the price of a few hundred bucks. But if you’re a DIYer, you may not prefer it.

If you’re likely to solve this problem of car ac yourself, here is your guide to fixing this problem. Let’s get going…

Items You Need:

How Would You Know if there is a Problem?

Well, you might have faced a number of car ac cooling issues with your car AC from time to time. But this problem that we are talking about, is quite a different one.

When you turn on the car AC, you expect it to blow hot air for the first few minutes. Because the cold air takes some time to get produced.

Over time, the AC cycles the air and turns it into a cool one. But what if the car ac doesn’t blow cold air at all? What if it keeps blowing hot air all the time?

Yeah, that’s our problem. And we guess, you’re suffering from this problem right now.

No, your car AC didn’t forget to turn the air cooler. There is probably a problem that you need to take care of.

What happens when Car AC Stopped Blowing Cold Air?

No matter whether it’s your home ac or the car ac, there is a device named a condenser in each of them. Its job is to cool the warm refrigerant, and that makes the air cold when it reaches the evaporator.

This condenser has cooled fans to push the air through. And that eventually cools the refrigerant.

Sometimes, the coil may get dirty and stay out of order. Sometimes, it might get clogged as well. So, the air wouldn’t come cold from the dirty car ac condenser anymore.

And that’s probably what happened in the case of your car ac as well.

Things You Need to Know Before Car AC Condenser Cleaning

Before answering the question, we would like to answer some of the questions that are closely related to the problem we are talking about –

  1. How long are you driving the car? Is the AC filter old enough?
  2. When warm air is coming out, is it coming from all the vents of the ac?
  3. Does this problem occur all the time? Or it’s occasional?
  4. Does the control panel of the AC unit work properly?
  5. When does it happen? Is it in the middle of driving or while the car is stopped?

If you have the answers in hand, let’s go through the solution that you need to do –

Steps of Cleaning The Car AC Condenser Coil

This part of the content contains the solutions to the problem for which you are here. In this part, we’ll learn how to clean car ac condenser coils, as this is the probable reason for your problem.

Step 1: Unassemble the Car AC

First things first, you need to open up the car ac. If you’re dealing with car troubleshooting by yourself, you should have enough ideas on how to do that.

You’ll need a set of screwdrivers to open up the cover. Afterward, you’ll be exposed to the ac fins. There should be screws with that as well.

Open up the fin, and let’s proceed to the next step.

Step 2: Clean the Fin

Before cleaning the condenser, clean the fin if there is any dust. Be certain to be able to handle the fins with care, because they are pretty lightweight and made of light aluminum.

Use a fin comb to get done with this step properly.

Step 3: Clean the car AC Condenser

To clean the condenser coil, you’ll need a water pressure washer. Make sure to get the best car cleaning pressure washer with a pressure controller.

Now, clean the coil from the car ac condenser from both inside and outside. To get done with that, don’t pour water onto the coil directly.

Because that might cause the dust and debris to get deep into the coil and cause more car ac condenser issues, which are unexpected!

First, direct the water pressure against the direction of airflow. This will push the dirt at the opening.

Step 4: Rinse off the Condenser

If you’re done with step 4, the debris and dust that are large and loose should be wiped away.

Now it’s time to take care of the stubborn and oily dust.

Take a water mixture with no less than the best detergent for the car wash. Make the mixture saturated enough. And now, immerse the condenser into the cleaning mixture.

Keep it for 10-20 minutes. Now, take a brush and start cleaning the coil smoothly. Remember not to be too harsh with the cleaning. That might damage its structure.

Step 5: Dry It Out

If you’re done with both of the steps, take the coil out and clean it off with the best air blower for the car.

If you don’t have a hot air blower, you may try it to keep it under sunlight or dry air. Make sure to have enough airflow at the place where you’re drying it off.


Throughout the steps of solving this car ac cooling issue, you might have noticed that a pressure washer had been used.

To have an insight into the whole summary, here is a relevant video to catch up:

Well, we want you to keep a few things in mind while handling this device in case of your car’s ac is cleaning –

  1. The fins of ac units are bent at near around 140psi. But the pressure washer would apply a force on the fin which is around 600psi. So, make sure to have a pressure washer that is controllable.
  2. Get a condenser needle for more precise operation. This will let you clean small openings like car ac fins with proper pressure.
  3. Make sure to have no water on the condenser while putting it back on the ac unit again.

I Hope, this guideline on how to fix car ac blowing hot air helped you to get done with the issue of car ac blowing warm air intermittently.


If your car’s AC is blowing warm air, you should stop driving and find the nearest auto repair service. The problem could be as small as a loose gas cap or something more serious like a leak in the hose that connects to the evaporator coil.

You can protect yourself from wasting time on costly repairs by checking these simple things first so it’s worth taking five minutes now to make sure everything is tight before starting your journey again.

How do you know if there’s an issue with your AC?

First, check for any visible leaks around hoses connections to each other or around where they connect to various parts of the vehicle.

Next, look at all bolts holding down brackets and clamps- are they tight enough?