Air Conditioner Not Cooling Heres Why
The last thing you want during the summer is for your air conditioner breaking and not cooling properly. You would know right away that theres something wrong with your air conditioning unit when its no longer giving you the right level of comfort. When this happens, its time to see if its something you can fix yourself or if its time to call an AC technician.
So, why is my air conditioning not cooling?
If your air conditioner is not cooling, its usually due to at least one of these 10 issues:
Some of these problems are easy to fix yourself, meaning you wont need to call the dreaded AC repairman. However, how do you troubleshoot, how do you fix the problem on your own, and when is it time to throw in the towel and call a professional?
In this guide, Im going to answer all of those questions and teach you how to handle the most common AC issues a homeowner might face.
Lets get to it
Condenser Unit Is Blocked
As previously described, your central air conditioning system likely includes an outdoor condenser unit. The exterior of the condenser unit features a large outdoor coil, which wraps most of the way around the outside of the unit. The coil includes a series of thin metal fins which are spaced very tightly together. If your air conditioner is running, but not lowering temperatures inside, one issue could be a blocked or clogged condenser coil. When operating correctly, the condenser fan draws air into the outdoor unit through the condenser coil to pull heat energy out of your home. Dirt, grass and other airborne debris can accumulate between the fins, clogging the coil. A dirty coil can lead to reduced energy efficiency, lack of cool air from the registers, or in extreme cases, complete system shutdown or damage to the compressor from overuse. You can attempt to clean the coil by clearing away debris, carefully vacuuming the coil with a brush attachment or rinsing gently with a hose. If your system still isnt cooling, its probably time to call a pro.
Ac Running But Not Cooling
In this article we are specifically addressing what to do if you air conditioner is running but not cooling the house. It’s fairly obvious that you need to find an air conditioning company when your AC is NOT running. But what do you do when your AC is running but not cooling?
Put The Problem In Perspective
There are two questions you should ask yourself when you notice your AC unit running but not cooling. First, you need to ask yourself “How long has this been going on?“. Secondly, “What is the temperature outside?“.
Most people don’t realize that air conditioners are meant to be “fine-tuned” for your specific location. In Orange County and Seminole County, we only surpass 93 degrees 1% of the year . That means that a “fine-tuned” air conditioning system will operate normally as long as the temperature is below 93 degrees. However, once the outside temperature exceeds 93 degrees, you will notice your ac not cooling enough even though it’s running.
Chart of average temperatures in Orlando, FL. Courtesy of www.weather-us.com
While this can be frustrating on those 1% of extremely hot days, the payoff is that your fine-tuned air conditioner will do its job properly the other 99% of the year.
So before you spend too much time and energy trying to solve a problem, make sure it’s truly a problem. Ask yourself if the temperature is above 93 degrees and is this an ongoing issue? If not, wait it out and more than likely you’ll be comfortable again in no time.
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Thermostat Is Set Incorrectly
When you notice your home getting a little hotter than normal, first check the thermostat settings. Be sure it is set to cool. If the thermostat is set to cool, check the temperature setting to be sure someone hasnt changed it. If it is off, set to heat, or set for constant fan , switch it back to cooling operation. After the system kicks on, wait a few minutes, then check for cold air blowing from the registers. If its cold, problem solved! If not, move on to the next troubleshooting tip checking the air filter.
The Coils Are Frozen Or Dirty

While your ACs filters do a great job when it comes to keeping the evaporator coil clean, the coil can also experience problems over time.
Coils tend to get dirty over time because they stay humid and its easy for mildew and mold to build up. This can adversely affect their functioning. Coils can also freeze over and stop working, particularly when theres not enough refrigerant in the system.
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Working With An Hvac Company
If the performance of your system still has not improved after performing these basic maintenance measures, it may be time to bring in a certified HVAC technician to diagnose the source of your troubles. Like any profession, there are many incredibly knowledgeable certified technicians who will work to ensure your air conditioning needs are met, and will do so at a fair price. Unfortunately, there are also unscrupulous HVAC technicians who may take advantage of their expertise to charge you more than your share.
Ask friends and family members for recommendations and research online reviews of HVAC companies in your area. The best ones will often have a vocal group of supporters in your community. Make sure your HVAC service provider has a 24-hour emergency number and enough staff on hand to give you enough attention even during the most sweltering summer months.
Filed Under: A/C & Heating, How To, HVAC & Central Air Conditioners, Lifestyle, Tips, Tricks & Life HacksTagged With: air conditioner, air conditioning, central air conditioning, home, home-living, HVAC, troubleshooting
About Our Team
Erin is a native Austinite that loves writing, wikipedia, online window-shopping for home goods, and riding on airplanes. When not writing articles at work, you can probably find her winding down with a glass of wine, a book, and her two favorite neurotic cats.
Problem : Dirty Air Filter
A dirty air filter reduces airflow into your AC, causing several problems:
- AC struggles to circulate enough cool air to get your home to the desired temperature .
- Evaporator coil literally freezes, turning into a block of ice that blocks air, meaning that your home gets very little cooled air at all.
Solution: Check the air filter and change it if it looks like the filter on the right
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Why Is My Air Conditioner Not Cooling
Weve all been there. Sweating through a sleepless night…or slogging through the heat of a sweltering July afternoon. Its no fun when your air conditioner is not cooling, but it can happen. And when it does, its not going to be in the dead of winter. Itll be the hottest day of the summer, and no matter how many times you turn down the thermostat you still find the AC not blowing air that is cold enough.
Air conditioning systems are more than just the condenser unit sitting outside your home. Typical split-system air conditioners have a lot of moving parts, including an indoor air handler unit , an evaporator coil, air filter, thermostat and copper tubing that connect the indoor and outdoor units. So there are a number of answers to the question Why is my air conditioner not cooling the house? But fear not. Just because your system isnt cooling, doesnt automatically mean expensive AC repairs or replacing the entire system.
Most homeowners can do some basic troubleshooting and may be able to resolve the issue. However, there are also times that youll need to make the call to your local Carrier® dealer for professional air conditioner service.
You Have A Wrongly Sized Unit
Most homeowners make a common mistake of buying an AC based on their budget rather than the house requirements. If you install an undersized unit, it will not adequately cool a large house. On the other hand, if you go for an oversized AC, it will cycle on and off often, so it wont consistently cool the house. Always ensure that you purchase an AC with the suitable capacity to cool your space. Consult an HVAC technician to help you choose the right unit based on your homes square footage, the number of occupants, and climatic conditions in your region.
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Why Is My Ac Not Cooling How To Fix
If you’ve been running your AC all day and night and still feel like you’re living in an oven, this post is for you! You have an AC not cooling, it’s hot ,and you’re not getting the cool air you need. Suddenly, you’re stuck in a sweltering house with no relief in sight! So what can you do if your AC isn’t cooling? Read on to find out the most common causes of why your central AC might not be cooling and how to fix them in this blog post. Stay chill folks!
Cool Your Home Now With An HVAC Pro
How Can I Tell If My Ac Compressor Is Not Turning On
It may be difficult for you to say with 100% certainty if your compressor is broken and not turning on. However, there are several signs to look out for. You often need special equipment and gauges to know which part of the air conditioner is causing the problem.
The compressor may be the problem when:
Your compressor is silent . You should hear it when its running.
The circuit breaker keeps tripping.
But dont forget: just because you cant hear the compressor, that doesnt necessarily mean the problem isnt coming from elsewhere in the air conditioner.
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Ac Not Cooling Hot Or Cold Spots In The House Check Air Vents
Its common for furniture, drapes or temporary items like toys, to block air vents in the house. Again, obstructions to airflow cause your HVAC system to work harder, increasing the likelihood of an AC repair.
Its common to have blower motor issues, frozen evaporator coils or water leaking from your air conditioner due to poor airflow. Return vents are usually larger squares or rectangles and draw air into the ducts.
They are sometimes high on the wall, but sometimes below knee-level. Supply vents are the smaller rectangle vents on the floor or up high on the ceiling.
The Registers Are Dirty Or Blocked

Your air conditioners registers can get dirty over time, just like the filters. This especially happens when you forget to clean registers regularly.
Sometimes they get blocked, which is very bad for air flow. Sometimes homeowners block them on purpose because they arent using a particular room or furniture gets placed in front of them by mistake.
Dirty or blocked registers force your AC to work much harder, increasing your energy bills without effectively keeping your home cool.
While this problem is among the most common AC issues, its relatively easy to address. Simply remove your ACs registers and give them a good vacuuming to remove any debris or run them through the dishwasher. And, unblock any registers that might have been closed.
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How Long Does An Ac Compressor Last
AC compressors should last 10-15 years…when the air conditioner is regularly maintained. As mentioned, the compressor works hard and therefore deals with normal wear and tear, but it has to work much, much harder when the air conditioning isnt well-maintained. That increases wear and tear and the chances of you ending up with a faulty compressor over time.
Why Is The Ac Not Blowing Cold Air
From very simple issues like a thermostat set incorrectly or a dirty filter…to a more complex situation that requires replacing components…there are a wide variety of reasons why you may find your air conditioner running, but not lowering the temperature in the house. Well outline some items you should check before calling a professional here. For a little more detail, visit our troubleshoot an air conditioner page.
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Air Conditioner Not Cooling Still
If you have done what you can, but you still need helping fixing an air conditioner not cooling, then we invite you to contact Pro-Tech for your air conditioning service. We have served Central Florida since 1961 and we service all makes and models of equipment.
If you want to ensure that your AC continues to run efficiently for years to come, we also invite you to sign up for our preventative maintenance program.
Contact us today to get immediate help fixing your air conditioner.
Common Causes Of Air Conditioner Not Blowing Cold Air
We have broken down each cause into 3 sections to help you out:
In some cases, you can pinpoint the problem yourself with the help of this guide. You might want to DIY fixing the AC not blowing cold air yourself, or call an HVAC professional.
In any case, knowing a thing or two about what causes AC units to stop blowing cold air will enable to you fix the problem or expedite the whole process with an HVAC professional.
We can categorize the issues that might lead to the AC unit not blowing cold air into 3 categories:
You can check issue one by one and see if you can make the air conditioner blow cold air again:
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Space Issues And Your Ac Load
1. Blocked registers and ventsThis problem happens all too frequently in both homes and office spaces. Furniture gets moved so that it blocks AC registers or vents. Sometimes, you close the grilles over the winter and forget to open them again when the AC is turned on for summer. Especially in office spaces, people even close or block registers intentionally. In fact, its one of the most common results of thermostat wars that happen when some workers are too hot and others are too cold.
This could very well turn out to be the reason your AC is not cooling, and its an easy fix. Take a walk around your space, and check all the vents and registers to make sure they are open and accessible.
2. Too much sunDo you have lots of south and west-facing windows? Sun-worshippers may prefer to leave them uncovered, but all that hot sun is adding a significant load to your AC. If your AC is not cooling enough, try installing blinds or shades that you can close during the hottest part of the day.
3. Too much humiditySometimes its not the temperature but too much humidity that makes it feel like your AC is not cooling. In muggy weather, your AC might not be able to remove enough moisture from the air to make you comfortable, even if the space is at the set temperature.
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BONUS: These steps also save you money on your energy bills.
The Ac Unit Is Too Old
As with everything else, air conditioners will get older year after year. Once the units have aged significantly, they tend to work much less effectively. Its cooling ability may have diminished with old age, so the air conditioner wont cool enough even when you optimized all the settings.
While regular repairs and maintenance can prolong the lifespan of your AC, the equipment will need to be replaced when it reaches the end of its operating life. Consult with an HVAC professional to dispose old air conditioners and get a brand new system installed.
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Air Conditioner Is Freezing Up
While air conditioners are meant to cool your house down, they arent meant to freeze or have ice and frost buildup. An AC unit freezing up can mean your clogged filter caused a dirty coil , the condensate line is blocked, low refrigerant, or that your thermostat settings are wrong- Either set too low, or the outdoor air is too cold.
Air Conditioner Fan Blowing Butnot Cooling

Step #1: Check For Leaks
Refrigerant leaks are a common culprit when it comes to an air conditioner thats not cooling enough. Common symptoms of a refrigerant leak include a hissing sound coming from the unit, frozen coils, and an air conditioner fan thats blowing but not cooling. You also have to check and clean your AC drain lines to avoid any leaks from the outside.
Read more about this issue in our article about how to fix a leaking air conditioner. Unless you have experience with repairing such leaks, youll need to contact a professional as some older types of refrigerant can be hazardous.
Step #2: Adjust Your Humidifier
If youre running a humidifier somewhere inyour home, that could also be to blame for your central air conditioner notcooling properly.
If the humidifier is running too aggressively,it will actually cancel out the coolness that your air conditioner isproducing. As a result, youll feel warmer in your home even though the airconditioner is running just fine.
If you suspect this might be the issue, lowerthe humidifier and see if that changes things. Unless you need it for somethingspecific, you can even try turning the humidifier off completely.
Step #3: Consider Your AirConditioners Size
Step #4: Check The Filter
Step #5: Clean The CondenserCoils
Nows also a good time to make sure you haveplenty of clearance on all sides of your outdoor unit. It the unit is flankedby plants or anything else, it will not be able to ventilate properly.
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