Guide to Fixing Your Air Conditioner That’s Not Blowing Cold Air

Last Updated on April 6, 2023 by Kimberly Crawford

Having an air conditioner that does not produce cool air can be extremely frustrating and uncomfortable during hot summer days. Not only does it make your home or office uncomfortably warm and stuffy, but it can be a waste of energy when the air conditioner is running without providing any cooling benefit.

It can also cause your energy bills to skyrocket due to the continual use of electricity. Knowing how to troubleshoot this issue and determine if it requires professional repair or just minor adjustments can save money and time in the long run.

Understanding the underlying causes of a non-functional air conditioner can be very helpful in diagnosing and correcting the problem. Common culprits include debris, blocked vents, faulty motors or compressors, Freon leaks, thermostat malfunctions, and electrical components. All of these issues need to be checked if your air conditioner is not producing cool air.

Possible Causes: Uncovering the Common Culprits Behind Air Conditioning Woes

air conditioning air problem

Insufficient refrigerant levels

Refrigerants are the chemicals that are used to cool air inside an air conditioning system. When there is a low level of refrigerant, it can prevent the system from cooling properly. Symptoms of low refrigerant levels include weak airflow and a loud noise coming from the outdoor unit.

Blocked or restricted airflow

Airflow is an essential part of the cooling process in an air conditioning system. If the airflow is blocked or restricted, it can reduce the amount of cool air being produced and cause the system to work harder than necessary.

Common culprits of blocked airflow include dirty air filters, debris accumulation on the condenser coils, and blocked vents or ducts.

Dirty air filters

Air filters are responsible for trapping dirt, dust, and other particles that enter the system.

When they become clogged, airflow is restricted and the system will not be able to cool as efficiently as it could otherwise.

Dirty air filters should be checked regularly and replaced when necessary in order to maintain optimal performance.

Additional possible causes

There are several other potential issues that can cause a system not to cool properly. These include faulty thermostat settings, damaged or malfunctioning components such as motors and compressors, Freon leaks, and electrical problems.

If these issues are suspected, it is important to contact a professional for repair.

Troubleshooting Steps: Taking Action When Your Air Conditioner Fails to Cool Your Space

Step 1: Check Thermostat Settings

Ideal Thermostat Settings: The ideal thermostat setting is typically around 78 degrees Fahrenheit, depending on the size and type of space being cooled.

If your thermostat has to be set much higher than this in order for the air conditioner to cool, then there is likely an issue with the thermostat or a bigger underlying problem.

Tips for Troubleshooting Thermostat Issues: If you suspect that the thermostat is the cause of your air conditioner’s malfunctioning, then try resetting it and checking the settings to make sure they are correct. If the issue persists, then it may be wise to call a professional for further diagnosis.

Step 2: Inspect and Clean or Replace Air Filters

1. Tools and Materials Needed: Check your owner’s manual for the exact size of filter that you need, as well as any special tools needed for installation. You will also need a vacuum cleaner, dust mask, and cleaning cloths.

2. Step-by-Step Filter Inspection and Replacement Process: Begin by turning off the power to your air conditioner at the fuse box or circuit breaker before removing the filter from its housing.

Visually inspect the filter for dirt, dust, and other contaminants, and if it is excessively dirty then replace it with a new one.

To clean the filter, first vacuum both sides to remove as much dirt and dust as possible, then wipe each side with a damp cloth. Once the filter has been cleaned or replaced, re-install it in its housing before turning the power back on.

Step 3: Examine and Clear Blocked Airflow

1. Identifying Areas to Check for Blockages: Inspect the ducts, vents, and coils of your air conditioning system for any obstructions or blockages that could be preventing airflow. Make sure the grills, louvers, and dampers are open and not blocked by furniture or other items.

2. Techniques for Clearing Blocked Airflow: If you find anything blocking the airflow of your air conditioner, gently remove it and then check to see if the system starts working properly again.

If the issue is more serious, such as a blockage in one of the ducts or coils, then you will need to call a professional for assistance.

Step 4: Inspect Refrigerant Levels

1. Warning About Handling Refrigerants: It is important to note that handling refrigerants can be dangerous and should only be done by a qualified technician. If you suspect that your air conditioner’s refrigerant levels are low, it is best to call a professional for further evaluation.

2. Recommendation to Call a Professional for This Step: A qualified technician will be able to accurately test the refrigerant levels in your air conditioning system and top them off as necessary. They can also diagnose any other issues that may be at play and recommend solutions.

Step 5: Damaged Heat Pump

1. Signs of Damage: If your air conditioner has an electronically commutated motor (ECM) heat pump, then check for signs of damage such as corrosion or cracks in the casing. Make sure all wiring is securely connected and look for any loose or broken components.

2. Troubleshooting Tips: If you find any signs of damage, then it is best to call a professional for further diagnosis and repair. They will be able to assess the issue, recommend solutions, and ensure that your heat pump is functioning properly again.

Step 6: Frozen evaporator coil

1. Symptoms of a Frozen Evaporator Coil: If your air conditioner is running but not cooling, then you may have an issue with the evaporator coil.

The most common symptom of this issue is ice buildup on the coil, which can block airflow and prevent the system from cooling properly.

2. Troubleshooting Tips: If you suspect your evaporator coil is frozen, then turn off the power to your air conditioning unit and allow the ice to melt.

Once it has been removed, check for any clogged or blocked drain lines, as well as any condensation that may be blocking the airflow of the system.

If these issues are present then clear them out before turning the power back on. If the issue persists, then it is best to call a professional for further diagnosis and repair.

Step 7: Choosing a Reliable Technician

1. Researching Qualified Technicians: When choosing a technician to service your air conditioner, it is important to do some research and make sure you select someone with the proper credentials.

Look for technicians who are certified in HVAC repair and have experience dealing with the type of system you own.

2. Checking References and Reviews: Ask for references from past customers or look for reviews online to make sure the technician is reliable and trustworthy.

You can also ask the technician for proof of their certifications or any other credentials they may have.

Air conditioner not blowing cold air but running after power outage

air conditioner not blowing cold air but running after power outage

After a power outage, an air conditioner may not blow cold air even if it is running. This issue can be caused by a number of factors, including loss of cooling agent in the system, insufficient refrigerant levels, a dirty condenser coil or compressor motor problems.

Issues with an AC unit should be addressed promptly in order to prevent any further damage and costly repairs.

Without prompt attention, the system could become less efficient, leading to an increase in energy bills and more frequent service calls. The compressor motor may even fail, resulting in a complete replacement of the unit.

Potential causes for this issue include loss of cooling agent in the system, insufficient refrigerant levels, a dirty condenser coil or compressor motor problems. Diagnostic steps to determine the cause of the issue include checking for blockages in the ductwork and inspecting the outside unit to assess any visible damage.

Potential Cause: Dirty Air Filter

A clogged or dirty air filter can slow down or block the airflow from your AC unit, resulting in a system that is not able to properly cool your home.

This issue can be compounded if the air conditioner has been running for an extended period of time, leading to a buildup of dust and debris in the system.

Signs of an obstructed or dirty air filter: The most common sign of a blocked or dirty filter is reduced airflow coming from the vents. You may also experience higher energy bills due to an inefficient unit, as well as unpleasant odors coming from the air conditioner.

How to check the air filter: Checking and replacing your air filter regularly is an easy way to help prevent a clog or blockage and maintain proper airflow. To do this, simply locate and remove the old filter, then replace it with a new one of the same size and type.

Solution: Replacing the air filter to allow proper airflow- Replacing a clogged or dirty air filter with a clean one is an easy and inexpensive way to help restore proper airflow in your system.

This can help ensure that your unit runs efficiently and helps keep dust, allergens, and other pollutants out of your home’s air.

Potential Cause: Refrigerant Leak

How a refrigerant leak may lead to a malfunctioning AC: Refrigerant is a key component in an air conditioning system and is necessary for the unit to be able to cool your home.

If there is a refrigerant leak, then the system can become inefficient, leading to a decrease in cooling capacity and an increase in energy bills.

Signs of a refrigerant leak, such as hissing sounds or oily residue: If the air conditioner is leaking refrigerant, then you may hear a hissing sound coming from the unit or notice an oily substance near the lines. You may also experience warm air coming from the vents, as well as high energy bills.

Steps to inspect the refrigerant level: To check for a leak, you can use a pressure gauge to measure the refrigerant levels in your system and ensure that they are at the recommended amount. You should also inspect all of the lines and connections for any signs of damage or wear.

Solution: Refilling the refrigerant and repairing leaks- If there is a leak, then you will need to refill the refrigerant and repair any lines that may be damaged. This should be done by a professional technician in order to ensure it is done correctly and safely.

Potential Cause: Faulty Thermostat

How a malfunctioning thermostat can result in the AC problem: A malfunctioning thermostat can cause your air conditioner to run even when the desired temperature has already been reached, leading to excessive wear and tear on the system as well as higher energy bills. It can also lead to the unit not being able to cool your home properly.

Signs of a malfunctioning thermostat, such as inaccurate readings: If the thermostat is not working correctly, then you may notice that it does not accurately reflect the actual temperature in your home. You may also experience frequent cycling on and off or strange noises coming from the unit.

How to check the thermostat: To check if your thermostat is functioning properly, you should first make sure that it is set to the correct temperature for your home. You can also try resetting or recalibrating the thermostat, as well as checking for any loose wires or connections.

Solution: Replacing the thermostat with a working one- If you determine that your thermostat is malfunctioning, then the best way to fix the issue is to replace it with a new unit. This should be done by a professional technician in order to ensure that it is installed correctly and safely.

Potential Cause: Dirty Coils

How dirty coils can cause an AC malfunction: Dirty or clogged coils in the air conditioner can prevent it from cooling efficiently, leading to a decrease in performance and energy efficiency. This can also result in unpleasant odors coming from the unit, as well as higher energy bills.

Signs of clogged or dirty coils, such as reduced airflow: If the coil is clogged or dirty, then you may notice that there is reduced airflow coming from the vents or that the air conditioner takes longer to cool your home. You may also see dirt or dust on the coils themselves.

Steps to inspect the coils: To check for dirt or clogs in the coil, you can use a flashlight and mirror to inspect the inside of the unit. You should also make sure that all of the vents are open and clear, as well as checking for any debris build up around the outside of the system.

Solution: Cleaning the coils- If the coil is dirty or clogged, then it can be cleaned using a vacuum cleaner or compressed air. This should also be done by a professional technician in order to ensure that it is done correctly and safely.

Additionally, you should make sure to regularly clean your air filter in order to prevent dirt and debris from building up on the coils.

Potential Cause: Leaking Ducts

How leaking ducts can cause an AC issue: Leaking ducts in your air conditioner can have a large impact on its performance, as it reduces the amount of cooled air that is delivered to your home.

This not only leads to an uncomfortable living space, but it can also cause a large increase in your energy bills.

Signs of leaking ducts, such as cold or warm spots: If the ducts are leaking, then you may notice that certain rooms in your home are warmer or cooler than others. You may also hear whistling noises coming from the vents, or feel drafts of air coming from them.

Steps to inspect the ducts: To check for leaks in the ducts, you can use a flashlight and mirror to carefully inspect the inside of your air conditioner. You should also make sure to check for any signs of damage or wear on the ductwork itself, such as cracks or holes.

Solution: Repairing or replacing the ducts- If there are any leaks in your ducts, then they should be repaired or replaced as soon as possible.

This should also be done by a professional technician in order to ensure that it is done correctly and safely. Additionally, you may need to have the ducts professionally sealed in order to reduce air leaks.

What temperature does AC stop cooling?

The temperature at which an air conditioner stops cooling depends on the type of air conditioner in use. Generally, window unit or split system air conditioners will stop cooling when the thermostat setting reaches approximately 78 degrees Fahrenheit.

Central air conditioning systems may be set to higher temperatures, such as 82-85 degrees Fahrenheit, before they stop cooling.

It is important to note that each air conditioner may have its own specific temperature settings, so it is important to refer to the user manual for your particular model for exact temperature specifications.

How many hours should AC run per day?

The amount of time your air conditioner should run each day depends on the size and efficiency of your AC unit, the outdoor temperature, and how well insulated your home is. Generally, you should run your air conditioner for about 8 to 12 hours per day in order to maintain a comfortable indoor temperature.

However, if temperatures are extremely hot and humid, you may need to run your AC for longer periods of time. Additionally, if your home is well insulated and temperatures are mild, you may be able to get away with running the air conditioner for fewer hours each day.

If you have a programmable thermostat, consider setting it so that your air conditioner runs less when you’re away from home or asleep. This can help you save energy and money on your energy bills. Finally, be sure to have your AC unit serviced at least once a year so that it is running optimally and efficiently.


Should I turn off the AC if it’s not cooling?

If your AC unit isn’t cooling, there are several steps you can take to troubleshoot the issue. First, check the power source and make sure it is plugged in. Then, ensure that all settings are correct, such as temperature and fan speed. If everything looks good but the AC still isn’t cooling, try cleaning the filters and checking for any debris blocking the air flow. If this doesn’t help, consider calling a professional for further assistance. In some cases, it is better to turn off the AC unit if it isn’t cooling, as this can prevent further damage or expensive repairs.

Does an air conditioner need to rest?

No, an air conditioner does not need to rest. An air conditioner works by taking in the warm air from a room and releasing it back as cool air through the refrigeration process, which involves compressing and expanding gasses. This process is continuous and continuous operation will not cause any damage to your AC unit. In fact, it is better to keep the AC running and allow for consistent cooling rather than turn it on and off frequently. Turning the unit off too often will actually reduce its efficiency as the refrigerant must be allowed to cycle through before cooling will occur again.


If your air conditioner is not blowing cold air but running, it could be caused by a variety of issues. Before you take any further action, make sure to troubleshoot the issue and determine the root cause. You may find that the problem can be solved with some simple DIY fixes, such as making sure your air filter is clean and changing the thermostat settings.

If the issue is more complex, it may be necessary to call an HVAC technician. No matter what, don’t hesitate to ask for professional help if needed as you don’t want the issue to worsen and cause any further damage to your air conditioner or home. In the meantime, take steps to stay cool such as using fans and staying hydrated.