Air Conditioner Is Not Blowing Cold Air: 10 Causes & Fixes

Are you worried because your air conditioner is not blowing cold air? This can be a major issue during the summer months, so it’s important to identify and address the problem as soon as possible.

Fortunately, there are many possible reasons why an air conditioner is not blowing cold air, and many of these reasons have easy solutions. In this post, we will dive in:

  • Why is your air conditioner not blowing cold air and their solutions?
  • And, how can you prevent your AC unit from blowing hot air instead of cool air in the future?

Let’s get straight to the point!

Why Your Air Conditioner Is Not Blowing Cold Air? 10 Causes And Solutions

Here, we’ll take a look at ten possible reasons why your air conditioner is not blowing cold air, so you can figure out what’s causing and how to fix it.

#1 Thermostat Settings is incorrect (Most common cause of air conditioner not blowing cold air)

Honestly, I’ve repaired several air conditioning units that aren’t blowing cool air, and most of them were resolved simply just by setting the thermostat settings correctly. The most common reason why your air conditioner is not blowing cold air may be because of incorrect thermostat settings. 

You should always check your thermostat first when you experience this problem. If the thermostat is set too low, a large amount of energy will be wasted, and if it is set too high, the AC will not blow cool air. 

So make sure your air conditioning thermostat temperature setting is lower than room temperature, usually, around 68 degrees Fahrenheit or at least 5 degrees Fahrenheit lower than your room temperature. And if you have a programmable thermostat, you can even set a schedule so the AC runs at the optimal time.

Also, I would recommend that you check the fan setting on your thermostat; If it is set to “On” then it may be causing the air conditioner to blow hot air. Set the fan setting to “Auto,” as this will ensure that the fan only runs when the compressor is active and isn’t constantly trying to cool your room. 

Now check whether your air conditioner is blowing cold air or not and if not then let’s proceed further.

#2 Blocked Air Vents

After the thermostat, the second most important thing to check is the vents. It also counts on the top of the list of common reasons for an air conditioner not blowing cool air. Over time, dirt and dust build up in the vents, preventing cool air from circulating throughout your space. You may also notice that some areas of your room are a bit warmer than others if air vents are blocked. 

Not only that but a blocked vent can cause your unit to freeze. If you suspect this issue, read this post: How to stop the air conditioner from freezing up?

Anyway, check your vent and if clogged, it needs cleaning. This will not only solve the problem but also ensure that air can flow freely through the system, thus cooling your home quickly and indirectly saving you money on energy bills. Cleaning the vents is a super easy process, you can do it yourself and can be done with a vacuum cleaner and brush attachment. Here are the steps of cleaning the air vents:

  1. Begin the process by unplugging the unit and removing the vent grill.
  2. Vacuum out any dirt and debris that has accumulated in the vent. Take care not to damage the wings.
  3. After vacuuming, use a brush to remove any excess dirt. Be sure to get into all the crevices of the vent to make sure it’s thoroughly cleaned.
  4. After you’ve finished cleaning the vents, reattach the vent grill to the unit and plug it back in.
  5. Check to be sure that air is now flowing freely through the unit.

If you notice that the air is still not as cool as it should be, then maybe that wasn’t the problem, so move on.

#3 Drain Pipe is blocked

The drainpipe is an important part of your air conditioning system, helping to remove any moisture that builds up in the system during the cooling process. When the system cools the air, it also removes moisture from the air. 

This moisture collects in a tray or pan inside the unit, and needs to be drained out of the unit through the drain pipe. And if the drainpipe is blocked or clogged, condensate will not be able to drain properly from the unit and will stop the unit cooling. This can be caused by debris, such as leaves and dirt, building up in the drain pipe, or maybe the drain pipe is leaking or bent.

Now you know how important it is to take care of the ductwork and clean it from time to time, so it’s free of blockages and you can get the most out of your AC. In my opinion, the best way to unclog clogged ductwork is to use a vacuum cleaner to blow out the dirt and debris. 

You also use a garden hose to clear the blockage. Once the blockage is removed, turn on your unit and check that your unit is blowing cold air. I hope the issues are resolved this time, and if not then there may be some other reason.

Learn more: How to Clean Air Conditioner’s drain pipe?

#4 Fan Issues

If your air conditioner fan is not working properly or not working at all, it will not be able to circulate cool air. This could be due to a faulty motor or a bad belt, if so then both the motor and the belt need to be replaced. Also, the fan can become clogged or blocked with debris, which prevents it from spinning properly. You will also hear rattling noises from the unit if there is an issue with the fan or the motor. 

And it’s time to clean the fan and motor or replace the fan or fan motor. Replacing a damaged fan or fan motor is not as easy as cleaning them, it is a complicated process and should be done by a trained technician.

If you do this yourself, you may damage other parts of the unit and create a more complex problem, and of course, a trained technician will do his job well by making sure that no other parts get damaged. I know, it will be expensive but it is totally worth it, it makes your air conditioner run smoothly and efficiently.

Although you can clean the fan and motor yourself, here are the steps to clean the fan and motor.

  1. Remove the outer cover of the unit.
  2. Use a soft brush or a vacuum cleaner with a brush attachment to remove any dust and debris from the fan blades.
  3. Use a damp cloth to wipe the motor.
  4. Put the cover back on and turn the unit on.

#5 Compressor Issues

The compressor is known as the heart of the air conditioner and its main job is to pump refrigerant around the system to cool the air in your space, and if it fails, the AC may not generate cool air. 

Problems with the compressor can occur due to a faulty motor, bad wiring, damaged capacitors, or a bad pressure switch, but the bigger one is the refrigerant leak. If there is no or low refrigerant at all, the compressor will not work as it should, and this causes your unit to blow hot air instead of cool air. 

And if your compressor get completely damaged then you need to replace it, signs of a damaged compressor include:

  • Unit is not blowing cold air or any air at all.
  • Noises like buzzing, humming or knocking coming from the unit.
  • Cause the breaker to trip or a fuse to blow.

If these signs meet then it needs to be replaced. And as an air conditioning expert, I have repaired several compressors of AC units. And in some cases, I have found that the compressor is working fine but its internal parts such as its capacitors or motor have gone bad.

So if the same thing is with you, then you need to replace the whole compressor. Getting an experienced HVAC technician to do this is important because they will be able to properly diagnose the problem and fix it quickly.

#6 Condenser is not working or it is ruined

If your air conditioner is not blowing cold air, one possible reason could be that your condenser is not working. The condenser unit is an important component of your air conditioner system that helps remove heat from your home and turn it into cool air. 

Some signs of a bad condenser or condenser not working can be:

  • Reduced cooling
  • Loud or unusual noises coming from the unit
  • Increase in energy bills
  • Temperature variations
  • Overheating of the compressor
  • Blown fuse

If you notice any of the signs listed above, your condenser is likely in poor condition or not working. And these issues can be caused by issues such as:

  • Debris buildup in the condenser coils
  • Clogged filters
  • Faulty wiring

So first check these above issues and fix them if you find any of these, you can clean the condenser coil by using a vacuum cleaner, and clean or replace the filter, by the way, if you don’t know even a little bit about wiring then you have a technician help you, and rule out faulty wiring.

But even after fixing these you still don’t see any results, then the condenser should be checked by an HVAC professional, and replaced if damaged.

#7 Issue with the ductwork

Ductwork is important to check when your air conditioner is blowing hot air. If the duct is clogged, leaking, or disconnected, it can result in blowing hot air instead of cool air. Signs of a clogged duct include: 

  • Dust accumulation
  • Musty or damp smell
  • Poor indoor air quality

To fix this problem, you’ll need to clean the ductwork with a vacuum cleaner or by hand. 

  1. Begin this process by removing any large debris or leaves that may be blocking the ducts. 
  2. Then, use a brush to scrape or remove dirt, dust, and other small particles from the walls of the ducts. 
  3. After that, use a vacuum cleaner to suck up loose particles and any remaining debris from the ducts, and you are done.

#8 Refrigerant Leaks or Low refrigerant levels

Refrigerant is a substance that helps cool the air in an air conditioner. If there is a leak, the refrigerant level is reduced. Low refrigerant levels can cause a number of problems, including the air conditioner not blowing cool air, reduced cooling power, and you may even hear noises from your AC unit. 

Signs of a refrigerant leak include hissing or bubbling sounds and frost on the copper lines connected to your outdoor unit. If left untreated, it can permanently damage your air conditioner and lead to more expensive repairs. 

If you think this may be the problem, then it is time to top up the refrigerant levels. But let me warn you first that this is the most difficult one, it is always recommended to do it with the help of an HVAC professional. Refilling refrigerant can be dangerous if done improperly and will do more harm than good, and it can even be dangerous to you, so keep that in mind. 

Before refilling with refrigerant, you need to fix any leaks in the system, this should not be ignored, otherwise, refilling it will be of no use, so be sure to fix the leak. Once any leaks have been repaired, safely refill refrigerant levels.

Learn: How to refill refrigerant?

#9 Frozen Evaporator Coils

Frozen evaporator coils can be another reason why your air conditioner is blowing hot air instead of cool air. When evaporator coils become clogged with dirt and debris, they can block the refrigerant and not circulate properly. 

This causes the air conditioner to be unable to cool your room because the evaporator coils are no longer able to absorb heat from the air inside your space. This blockage can cause frost to build up on the evaporator coils. 

Fixing the frozen evaporator coils it easy, just follow the steps:

  1. Turn off the power to your air conditioner.
  2. Remove the cover and locate the evaporator coil.
  3. Next, you’ll need to melt the evaporator coil. There are a few ways to do this, such as:
    1. Using a hair dryer
    2. Using a hot water bottle.
  4. Place one of these on the frozen spot for a few minutes until it melts completely.
  5. Once it’s completely melted, use a towel to blot up the moist water on the coils, and let it dry for a few minutes before putting the cover back on.

#10 Dirty Air Filter

A dirty air filter of an AC unit contributes greatly to every air conditioning problem. A dirty air filter is the biggest enemy of your air conditioning unit and if not cleaned or replaced from time to time, it can put your unit in huge trouble.

If the air filter is clogged with dust, pet hair, pollen, or mold spores, it will restrict airflow, making it difficult for the AC to cool the air and provide you with cool air. It doesn’t take long for the filter to clog, it can clog within less than a month in the summer when you are running your unit all day long. 

So clean the filter once a month and replace it after every 3 or 4 months to get good output, but replace it every 2 months to get the most out of it.

Cleaning the air filter

How to prevent your air conditioner from blowing hot air instead of cold air?

Around 20-30 air conditioners face the problem of ‘air conditioners not blowing cool air’, so it is a bit of a common problem, but it should not be that much.

Here, we’ll provide some tips to prevent your air conditioner from blowing cold air in the future to ensure that your air conditioner is working properly and blowing cool air all summer long.

#1 Give it a regular maintenance

How to Maintain an Air Conditioner

Neglecting the maintenance on your air conditioner is one of the indirect reasons for the AC not blowing cool air. Regular maintenance is important to keep your unit running as efficiently as it used to run. Think of your air conditioning unit as you or a human being, and maintenance as food. 

You’ll be more energetic and more productive if you feed yourself the best healthy food. But what if you neglect to feed yourself, then you will become less energetic and productive than before, and if you neglect to feed yourself long enough then you will become ill or even die, and the same thing happens with your air conditioning unit. If you properly maintain your AC unit then it will work efficiently and effectively, but if you neglect in giving the necessary maintenance needs then it will damage over time. 

That’s why it’s important to perform regular maintenance to keep your air conditioner running smoothly. Regular maintenance includes:

  • Checking the filter and changing it as needed
  • Cleaning the condenser coils
  • Cleaning the air vents
  • Cleaning the ductwork
  • Checking for any damaged or worn-out parts
  • Checking the refrigerant levels and refilling it, if needed
  • Checking and cleaning the fans and motors for smooth operation
We have a complete guide to maintaining air conditioning units, you can check it out here: AC Maintenance Guide

#2 Scheduling annual inspections

Performing an annual inspection of your air conditioning system can help prevent your air conditioner from blowing hot air, air conditioner freezing up, AC unit making noises, water leaking and so on. During an inspection, an experienced technician will identify potential problems that may be causing any issues to the unit. 

Common problems they can look for include broken parts, damaged wiring, and clogged filters. If a problem is found, it’s best to take care of it as soon as possible to prevent your air conditioner from blowing hot air and other problems in the future. An annual inspection can also be beneficial in identifying opportunities to improve energy efficiency. 

By doing this, you may be able to save money on utility costs. But as we all know; You have to lose something to gain something, which means it will cost a little but it is totally okay. However, if any part goes bad then it will be super expensive.

FAQ: Why is my air conditioner blowing warm air instead of cool air?

Here I’ll answer some of the most frequently asked questions about the topic. This will be super helpful for you so keep reading.

Q1. Is it necessary to call a professional to fix an air conditioner that is not blowing cold air?

Ans: It is recommended to call a professional to fix an air conditioner that is not blowing cold air when you fail to identify the causes and fix the problems. Calling a professional to fix the issue before you have tried to identify the cause and fix it yourself is a waste of money.

Q2. What are the long-term effects of an air conditioner not blowing cold air?

Ans: The long-term effects of an air conditioner not blowing cool air can lead to reduced energy efficiency, reduced comfort and health issues, and increased wear and tear.

Q3. What are the signs that indicate my air conditioner is not blowing cold air?

Ans: The signs that indicate my air conditioner is not blowing cool air could be you are feeling uncomfortable and feeling hotter than before.

Q4. How often should I maintain my air conditioner to prevent it from not blowing cold air?

Ans: You should maintain your air conditioner to prevent it from not blowing cold air twice a year for maximum output, once before the start of the summer season and once after the end of the summer season.

Wrap Up: Air Conditioner Is Not Blowing Cold Air

An air conditioner not blowing cool air can be caused by a number of issues that I mentioned earlier. It is important to check and resolve if anything is wrong with your AC unit, otherwise it is a total waste of energy. Regular maintenance and annual inspection is important to prevent such issues in the future.

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David Jack

David Jack

David Jack is a veteran when it comes to air conditioners, he love helping people find solutions to their problems with AC units. His specialty is helping people find the right Air-Conditioner for their needs, whether that means replacing a broken unit or adding on to an existing system. He is also great at diagnosing problems and fixing them quickly. He learned this from my father Jack Smith who was an air conditioner repairer, he has 2 years of experience in this field.

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