Why Is My AC Unit Not Blowing Cold Air?


As the summer heat lingers, we still rely heavily on our air conditioning units to bring relief and comfort. However, nothing can be more frustrating than when your AC unit fails to live up to expectations and stops blowing cold air. Not only can this be a nuisance, but it can also lead to increased energy bills as your unit works harder to cool your home.

In this blog post, Buckeye Heating, Cooling & Plumbing will discuss the causes behind an AC not blowing cold air and what needs to be done to fix them.

Clogged Air Filter

The air filter in your air conditioning unit performs a crucial role of cleaning the incoming air of any dust or dirt particles. Over time, this filter can become clogged, leading to decreased airflow and reduced cooling efficiency. A clogged filter can also cause your evaporator coils to freeze, further reducing cooling efficiency.

To fix this issue, you can replace or clean your air filter. Ideally, you should do this every one to three months, depending on AC system usage, filter type, and your home's indoor air quality.

Low Refrigerant Levels

Liquid refrigerant is essential to the cooling process because it enables refrigeration systems to transfer heat effectively. It is a fluid that readily changes from a liquid to a gas and back again, which makes it ideal for cooling. As refrigerant circulates through a refrigeration system, it absorbs heat from the indoor environment and moves it to the outdoor unit where it is released.

If your unit is blowing warm air instead of blowing cool air, it may be due to low refrigerant levels and refrigerant leaks. A refrigerant leak can be caused by a variety of reasons, such as a damaged AC coil or a loose connection.

Refrigerant leaks must be repaired by a certified professional, as it involves handling refrigerant, which can be hazardous. A technician will find the source of the leak and repair it before recharging the refrigerant to its optimal level.

Dirty Condenser Coils

The condenser coils in your AC unit is where the refrigerant releases heat and cools down. When the condenser coils are dirty, they can't effectively circulate heat, leading to reduced cooling efficiency.

To fix this issue, you can clean your condenser coils.

  1. Turn off the power: Before you start cleaning the coils, turn off the power supply to your AC unit. This will prevent any electrical hazards.

  2. Remove debris: Clear the area around the condenser unit of any fallen leaves or debris. This will ensure that there are no obstructions during cleaning.

  3. Remove the top grille: Most AC units have a top grille over the condenser coils. Remove this grille by unscrewing the fasteners or using a screwdriver.

  4. Clean the coils: Using a soft-bristled brush or a vacuum cleaner with a brush attachment, gently clean the dirt and debris off the coils. Be careful not to damage the fragile fins.

  5. Rinse with water: After cleaning the coils, rinse them with a gentle spray of water from a garden hose. Be sure to avoid using a high-pressure washer, as it can damage the fins.

  6. Check for damage: Inspect the coils for any damage, such as bent fins. If you find any, straighten them out carefully using a fin comb. This will ensure that the air circulates through the coils smoothly.

  7. Reassemble the unit: Once the cleaning is complete and the coils are dry, reattach the top grille to the unit. Turn on the power supply, and your AC unit is ready to work efficiently again.

If you're not comfortable cleaning the condenser coils inside your air conditioning system, call Buckeye to perform maintenance for your air conditioner, which includes coil cleaning.

Clogged Evaporator Coil

Dirty evaporator coils can significantly impact the performance of an air conditioner and cause it to blow warm air instead of cool, refreshing air. This occurs because dirt, dust, and other debris can accumulate on the coils and hinder the transfer of heat between the coils and the refrigerant. As a result, the refrigerant cannot absorb enough heat to cool the air passing over the coils.

To remedy this problem, it is essential to clean the evaporator coil. This should be done by a professional HVAC technician who has the appropriate tools and expertise required to safely and effectively clean the coils. By regularly cleaning the evaporator coil in your central AC system, you can keep your air conditioner running efficiently and effectively, saving energy and money on utility bills while ensuring your home remains comfortable year-round.

Faulty Electrical Components

A malfunctioning electrical component, such as the capacitor or relay, can also cause your air conditioner to stop blowing cold air. When these components fail, they can affect the compressor's ability to function efficiently and your air conditioning system may not blow cold air.

To fix this issue, it's best to leave it to a professional technician. They will diagnose the problem and replace any defective components so AC units blow cool air once more.

Leaking Air Ducts

Leaking ductwork in your home can cause it to feel like it's not blowing cold air, even if the unit is functioning properly. The leaks allow cooled air to escape before it reaches your desired space, leading to inadequate cooling and the system blowing hot air from vents. Not only does this cause a less comfortable environment, but it can also increase your monthly energy bill, as your AC system must work harder to compensate for the lost air circulating out of the ductwork.

Thankfully, fixing leaking air ducts is a straightforward process. A professional HVAC technician can identify and repair leaks, ensuring your system is working efficiently.

Blocked or Clogged Registers

Blocked or clogged registers can cause your air conditioner to feel like it is not blowing cold air. Registers are the vents that deliver the cool air throughout your home. When they become blocked or clogged, they interfere with the airflow and reduce the amount of cold air that can enter your living space. Common causes of blocked registers include dust, dirt, pet hair, and debris that have accumulated over time.

To fix this problem, you should start by making sure all registers in rooms around your house are open. Use a vacuum cleaner to remove any visible debris from the registers. If the problem persists, it may be time to consider having your air ducts professionally cleaned.

Wrong Thermostat Setting

Using the wrong thermostat setting can lead to the frustrating feeling of your air conditioner not blowing cold air into your home. More specifically, if the fan setting on your thermostat is set to ON, it will circulate air even when your air conditioner is not running. This causes warm air to blow out of your vents, creating the impression that your air conditioning unit is not functioning properly.

To fix this issue, make sure that the fan setting on your thermostat is set to AUTO. This will ensure that the fan only circulates air when your air conditioning unit is running, which in turn will blow cool air into your home. By avoiding the common mistake of setting your fan to ON, you can enjoy the benefits of a cool and comfortable indoor environment during the hot summer months.

Bad Blower Motor or Fan

A faulty blower motor or blower fan in your air conditioning system can cause your unit to stop blowing cold air. The blower fan, also known as the indoor fan, is responsible for pushing the cold air through your home's ductwork. When it or the motor that operates it malfunctions, it can't circulate cool air effectively, resulting in a warm feeling air coming out of your vents. It may also make strange noises and cause your system to freeze up due to inadequate airflow.

To fix this issue, you'll need to have a professional HVAC technician inspect the blower fan manually. They'll check on the fan belt, motor, and blade for any signs of damage or wear and tear. Depending on the severity of the issue, the technician may repair or replace the blower fan itself, ensuring proper airflow and the return of your cool, comfortable home.

Get Help When You Have an AC Not Blowing Cold Air

If you have an AC not blowing cold air, this is a concerning issue that can impact your home's comfort and increase energy bills. By understanding the causes behind this problem, you can take the necessary steps to fix it and restore your unit's cooling efficiency. Remember to always leave any intricate repairs to a certified professional to avoid any safety hazards and extend your unit's lifespan.

When you need help fixing an AC not blowing cold air, call the pros at Buckeye for expert air conditioner repair services. Contact us today to schedule air conditioning repairs.

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