Why is my AC blowing warm air?
There are very few things in the world worse than a broken AC unit in the middle of summer. During summer, we all want to stay in a comfortable house away from the heat. However, your AC unit may stop blowing cold air, and it can be quite frustrating.
Image by F. Muhammad
Unfortunately, this is a common problem for many homeowners during the summer. There may be many reasons why your AC isn’t blowing cold air into your home. You can easily fix these issues without requiring professional assistance.
Below are five common reasons why your AC isn’t blowing cold air in your home and what you can do to troubleshoot the issue.
1.Thermostat Setting
While it’s tempting to contact a professional when you notice a malfunction in your AC, it’s essential to check the thermostat first. Some minor thermostat issues may result in the AC unit’s malfunction.
Problems with the thermostat are often not serious but cause gradual or sudden fluctuations in your AC unit’s performance. When a system’s functionality is affected, you could misinterpret the symptoms as something serious that requires urgent repair or replacement. Most often, this is not the case, and a simple fix could change everything.
A defective thermostat may be the cause of problems such as the following.
The AC Stops Working Suddenly
If your AC unit stops working suddenly, you want it to be fixed immediately to avoid the summer heat discomfort. While it’s common to ask yourself, “Is there any AC repair near me?” ensure you check the thermostat before contacting a technician.
The first step should be checking whether the thermostat display is on. If your thermostat is off, it will not communicate with the AC to power it on. Check whether the thermostat has batteries, confirm that the fuse isn’t blown, and there is no tripped breaker in your electric service panel.
If you’re sure that the thermostat is receiving enough power to keep it running, take the following steps:
- Switch off the breaker connected to the thermostat
- Take off the thermostat’s cover to inspect its internal components
- Check for dirt, smoke, dust, or soot buildup
- Carefully clean the thermostat with a soft brush or a canned compressor
- Put back the covering and check whether it’s working
Dust, debris, and soot could affect how your thermostat works. Ensure you clean out all the debris to avoid buildup.
The AC Unit Doesn’t Cool Down Your Home
If you notice any temperature discrepancies between your thermostat and the room temperature, poor installation could be the reason. This could leave a level thermostat off-kilter. To correct this issue, place a carpenter’s level underneath or above the thermostat and readjust its position so that it’s level.
A wrongly placed thermostat can fail to regulate your home’s temperature as expected. Ensure your thermostat is set at the correct location within your home. Avoid placing it in an area with direct exposure to heat sources such as direct sunlight or cold drafts.
Continuous Running of the AC and Frequent Shot Cycling
Dirt buildup inside a thermostat could trigger your AC unit’s continuous running and short-cycling, which reduces your AC’s efficiency. After a thorough clean-up, your AC should get back to normal functioning. However, if it doesn’t ensure, you contact an HVAC contractor for an inspection.
Below are other causes of AC short cycling:
- An oversized AC unit
- Lack of enough refrigerant
- A worn-out low-pressure control switch
- Poorly placed thermostat
While you may think it’s okay to install an oversized unit to cool your space faster, this could be a mistake. An oversized unit may experience frequent short cycling to maintain your preferred temperature.
One of the best ways to prevent short-cycling is by scheduling regular maintenance and inspections of your unit.
2.Clogged Air Filters
Air filters sift dirt and debris particles from your indoor air supply. When these particles fill up your unit’s air filter to capacity, they lead to clogging. Less air will pass through a dirty air filter.
When less air passes through your air conditioning unit, your home’s temperature will take longer to cool down. For example, your thermostat may read 72 degrees, but your indoor air will not go below 81 degrees.
A clogged air filter could also lead to the freezing of the evaporator coil. A frozen evaporator coil acts as a block of ice, preventing cold air from entering your home. The best remedy for a clogged filter is replacement or cleaning.
Follow the below steps to clean a dirty air filter:
- Fill up a bucket with clear water and add a little laundry detergent
- Remove the clogged filter and submerge it in the bucket of water
- Slowly swirl it around and use your hands to remove the buildup from the filter material
- Remove the filter from the water and carefully shake off excess water
- Rinse it off with clean running water and let it dry
HVAC experts recommend that you should replace air filters after every two to three months. A clogged air filter could lead to other problems such as overheating the motor causing extensive damage to your AC unit.
3.Low Refrigerant Levels
While most people believe that your AC’s coolant could get depleted or go bad, this is a myth. Low refrigerant levels are among the biggest reasons why your AC unit might not be blowing cold air.
Refrigerant leaks could be the reason behind low levels.
If your AC has low refrigerant levels, checking the lines and recharging the system is the perfect remedy. This will get your AC blowing cool air throughout your home again. Unfortunately, checking the lines and recharging the system is a very complicated process that requires a professional.
Depending on the amount of work required and your AC unit’s age, your contractor will advise if a replacement is the best option. A system upgrade is the best choice if:
- Your unit is over ten years old
- Excessive overall repair costs
- You are consistently experiencing the same problems
When it comes to your AC unit, prevention is better than cure. Scheduling regular professional maintenance and inspections will help your unit work efficiently and avoid potential breakdowns.
4.Broken Air Ducts and Faulty Compressors
A compressor is the main component of your AC unit, acting as the heart of the system. Its primary purpose is to move the refrigerant between the outside and the inside units.
A faulty compressor can be costly to repair because it requires a replacement of the outside unit. Due to the complexity of the work involved, it’s advisable to have a professional handle the process.
Your unit’s duct system transports cooled clean air into your home. Duct systems are mostly placed in the attic. When the duct is damaged, hot air from the attic slips through the vents and into your house, making it look like your AC is blowing warm air.
Air ducts wear down with time or because of installation mistakes. Rodents can also damage your air ducts. Ensure you schedule a professional inspection of your air ducts by an HVAC technician to diagnose any possible issues.
5.Ice Buildup
Even during hot summer months, your AC unit can freeze, leading to ice buildup. This is a sign of an underlying problem.
The most common reasons for a frozen AC include poor airflow and low refrigerant levels.
Improper airflow means that your AC is not receiving enough airflow to operate optimally. Inadequate airflow could lead to the coils dropping below the freezing point. The humidity around the air forms water droplets around the coil.
Due to the collection of the humidity on the coil, ice builds up on your AC. Insufficient airflow in your unit could be caused by:
- Clogged and dirty air filter
- Inadequate return ducts
- Restrictive air filter
- Unclean evaporator coils
- Damaged or wrongly sized ductwork
Ice buildup is a common problem for many homeowners. However, before calling a technician, try cleaning or replacing your air filters. If this doesn’t work, contact your HVAC contractor to take a look at the AC unit.
Now You Know What to Do if Your AC Isn’t Blowing Cold Air
The last thing you want during summer is your AC blowing warm air. If your AC isn’t blowing cold air, there could be an underlying problem. While the issue might be as easy as resetting your thermostat, often it’s due to more complex issues such as refrigerants and condenser coils.
Following the tips outlined above, you could solve your AC system problems and save hundreds of dollars. However, if the problem seems too complex for you, ensure you contact a professional to assist.
For more informative tips about creating a better home environment, check out other posts on our blog.
