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Why Is My AC Not Blowing Cold Air?

Posted On July 30, 2024
air conditioner is not blowing cold air but running

On a hot day, nothing inspires panic like an AC that doesn’t blow cold air. Even with the best maintenance, there are times when you may need air conditioning repair services. With the right AC maintenance and repairs, you can prevent the underlying problem from becoming worse and enjoy a cooler, more comfortable home.

10 Common Reasons Why Your AC Might Not Blow Cold Air 

If your home feels unusually warm, check the vents for cool air. When ACs stop blowing cold air, the following AC repair issues may be at fault. 

1. Low Refrigerant Levels 

When your refrigerant level is low, you may notice the following symptoms: 

  • A frozen AC
  • Ice around the lines and coils
  • Warm air coming from your vents
  • Hissing or bubbling noises

If you have low refrigerant levels, you need professional AC repair services. The Environmental Protection Agency (EPA) requires technicians to get a Section 608 certification to recharge refrigerant. Because refrigerants impact the environment and human health, you don’t want to leave this problem untreated.

2. Clogged Drain Pipes 

Air conditioners are designed to pull moisture from the air. Then, the excess water is supposed to drain out of your machine using the condensate drain pipe. If this drain gets clogged by dirt and debris, water will stop draining, causing the AC to shut down as a fail-safe measure.

Luckily, this is one of the easiest air conditioner maintenance tasks to perform. You can clean out the drain pipe on your own or call a 24-hour AC repair company to remove the clogs for you.

3. Dirty Filters

Your AC may have more than one filter. You’ll most likely have one filter in your return vent and another in your air handler. If your filters become clogged, it limits airflow and stops your filter from working properly, causing the air conditioner to not blow cold air but run.

How often you need to change or clean the air filters depends on the manufacturer. While 30 days is a common frequency, some air filters don’t need to be changed for 60 or 90 days. 

It’s important to use clean air filters because dirty filters put added strain on your AC. Eventually, this strain can cause your AC to break down prematurely.

4. Power Issues 

If there are any power issues, it could prevent your AC from working correctly. For example, broken wires could prevent the air conditioner from getting enough electricity. 

When you’re dealing with electrical issues, it’s a good idea to shut off your AC until you can get emergency air conditioner repairs. Damaged wires and other electrical problems can be dangerous, so it’s important to leave these tasks to an HVAC professional.

5. Blocked Returns

Your air conditioner doesn’t just have vents to release cool air into your home. It also has vents that bring in air, which are known as returns. Normally, returns are placed in a central location in your house so that they can circulate air.

However, you’ll sometimes see multiple vents in a single room. One of these vents may be a return. If the return vent isn’t blowing cold air, it’s because it isn’t supposed to. Returns are designed to bring air in, not out. 

Sometimes, returns can get blocked by furniture, plants, or other items. When this happens, it prevents them from working properly. From time to time, check to see if your returns are blocked in any way. You should also clean the return and the filter inside it regularly.  

6. Tripped Circuit Breaker

Don’t be hasty about scheduling a new air conditioner installation. The issue with your AC could be as simple as a tripped circuit breaker, which is easy to fix. 

Typically, air conditioners use an inside and outside breaker. If the outside breaker trips, the vents will still work but will blow warm air. In many cases, fixing a tripped circuit breaker is as easy as flipping a switch. 

However, it’s important to pay attention to how often your AC trips the breaker. If this is a frequent problem, there may be an underlying cause. Faulty compressors, dirty air filters, broken coil fans, and refrigerant leaks can all trip the breaker. In some cases, you may even need to get an air conditioner replacement.

7. Damaged or Clogged Ducts

As you troubleshoot your AC repair needs, check the vents in each room. If some of the vents are able to blow cold air, your air conditioning unit is likely working fine. Instead, you may be dealing with a duct-related issue. 

When your ducts become dirty or clogged, it prevents cold air from getting where it needs to go. Instead of reaching your rooms, the air could be spilling out into your attic or a different space. 

Sometimes, duct-related problems are caused by a lack of pressure. If there’s not enough pressure in the ducts, they won’t be able to move air to your rooms. Issues with your blower fan can also prevent air from reaching distant rooms.

Other than inspecting ducts for clogs, you can troubleshoot duct issues by checking vents to see if air is reaching every one of your rooms. To prevent air leaks and improve your AC efficiency, make sure your ducts are adequately sealed. 

8. Dirty Compressor or Evaporator Coils 

Your compressor and evaporator coils are integral parts of your AC. Occasionally, you may need to call for air conditioning repair services to fix the coils. Sometimes, the problem is as simple as removing excess dirt, dust, or debris from the coils.

  • Cleaning Your Compressor Coils

Unlike the evaporator coils, your compressor is located outside your house. The compressor coils are intended to help your AC cool the air. However, the outdoor location means compressor coils can easily become dirty or clogged with plant matter. 

Luckily, you can easily inspect your compressor coils by looking at them. You should never touch them without gloves on because the coil fins are quite sharp. 

If the compressor coils are dirty, you can clean them by turning off the AC’s power. Then, use the water hose to remove dirt, dust, and weeds. An HVAC technician can do a more thorough cleaning during your routine AC maintenance.

  • Fixing Dirty Evaporator Coils 

Anything that makes it past your air filter can end up clogging your evaporator coils. Before opening any panels to check on them, it’s important to turn off your AC at the breaker box. It’s generally better to leave evaporator coil inspections to the professionals because these coils are situated behind a service panel. 

There are often lines in front of the evaporator coils, and these lines must be dealt with carefully. The fins are especially sharp, so you should wear gloves when working around them. A vacuum cleaner with a soft brush attachment can be used to remove debris and dirt that are near the surface of the coils. For an even cleaner result, an HVAC technician can use a special spray cleaner and brush.

9. Broken Capacitor 

The capacitor is normally responsible for sending a surge of electricity into your air conditioner to start it. These metal cylinders are located under the service panel in your outdoor AC unit. You should never deal with a faulty capacitor on your own. It stores a large amount of electricity, so you’ll get a horrible shock if you touch it. The capacitor must always be discharged before it can be handled in any way.

If you notice any leaks, ruptures, or bulges, your capacitor may need to be replaced. You can normally tell if there is a broken capacitor because you’ll stop receiving cold air. Additionally, you might hear a humming noise or smell something burning. 

When the capacitor is broken, it’s important to call an HVAC company to replace the AC and provide repair services. A broken capacitor is capable of melting plastic and causing damage to other parts, so you need to get it fixed right away.

10. Thermostat Problems

Before you start looking for the best AC installation in your area, it’s important to troubleshoot other issues, like thermostat problems. Your thermostat is responsible for turning your system on and off. If it isn’t working properly, it may stop signaling your AC to turn on when the indoor temperature rises. 

Depending on the thermostat type, you may be able to reset the thermostat or replace its batteries. Then, see if your AC starts blowing cold air again. If it doesn’t, you may need to get your thermostat replaced.

What Should You Do If Your AC Stops Blowing Cold Air? 

HVAC technician fixing AC unit

If your AC is blowing but not cold air, there are a few steps you can take before calling for 24-hour AC repair.

  • Evaluate the AC: Look for pooling water on the ground or a lack of air. Pay attention to any sounds or smells that are out of the ordinary. 
  • Check the Filters: Inspect the filters for dirt. If necessary, clean or change the filter. 
  • Look at the Breaker: You can turn a tripped breaker on again. If something keeps tripping a breaker, call for help because there may be an underlying electrical problem.
  • Clean the Coils: Dirty evaporator or condenser coils can make your system work overtime to cool your home. Cleaning these coils can help your AC cool your home more efficiently. 
  • Unblock Registers: Sometimes, people place furniture or houseplants over a register. Check your home’s vents and registers to make sure they’re open.
  • Seal Leaks: If you have leaky ductwork, cold air could be escaping before it gets to each room. Inspect the ducts and seal any leaks you find.

When To Call a Professional

So, why is your AC not blowing cold air? If DIY troubleshooting hasn’t helped you figure out why your air conditioner’s not blowing cold air but is running, it may be time to get professional help. Homeowners can safely handle filter changes, vent cleaning, drain cleaning, and thermostat checks.

If your AC stopped blowing cold air for any other reason, you need to reach out to our HVAC professionals right away. Our team has the experience and tools necessary for fixing refrigerant leaks, compressor issues, and wiring problems. By using a professional for your services, you can protect your warranty and ensure the repairs are handled safely. Before the problem gets worse, call one of our HVAC technicians for help.

Preventive AC Maintenance Tips

Once you’ve successfully fixed your AC, it’s important to prevent the same cooling problem from happening again. The last thing you want is to require an emergency air conditioner repair on a sweltering hot day.  With the following tips, you can keep your air conditioner blowing cool air. 

Seal Air Leaks

To get the most out of your AC, you need to seal any leaks in your ductwork. You should also inspect your home for potential leaks. Windows and doors are common spots where cold air can escape. When this happens, your AC has to work extra hard to keep the air cold. 

Insulate Properly 

You can reduce your electricity bill by improving the insulation in your home. Good insulation prevents cold air from leaving. Other than reducing your power bill, insulation can prevent repairs because your air conditioner won’t have to work as hard to keep your home cold.

Get Routine Maintenance 

Your air conditioner is supposed to get routine maintenance at least once a year. Ideally, this should happen before the summer. During this visit, an HVAC technician will inspect your AC for wear and tear. They’ll clean the AC’s parts, diagnose issues, and recharge the refrigerant. With proper maintenance, you can prevent future breakdowns. 

Change Your Air Filter

If your air conditioner’s not blowing cold air but is running, it may be time to change your air filter and perform routine maintenance. Your air filter should be changed every one to three months to protect your AC.

Clean Evaporator and Condenser Coils

You can protect your AC from wear by cleaning the evaporator and condenser coils. The condenser coils can be cleaned with a hose after the AC has been switched off. Be careful not to bend the delicate fins. While your outdoor coils can be cleaned on your own, the indoor coils should be left to the professionals.

Schedule Your Thermostat

If you don’t have a smart thermostat, it may be time to invest in one. By scheduling your smart thermostat, you can save energy and reduce the amount of wear on your AC.

Perform Seasonal Checks

To keep your AC functioning at its best, make sure to clean and test your cooling system in the spring before it is used all the time. In the summer, you should monitor its performance and continue completing your routine maintenance tasks. When winter rolls around, prepare your HVAC system for your wintertime heating requirements. As winter begins, make sure your AC’s outdoor unit is protected from the elements.

Homeowner Checklist for Seasonal HVAC Maintenance

  • Change the air filter every one to three months.
  • Clean the condenser coils. 
  • Remove debris from around your outdoor unit.
  • Clean the vents.
  • Monitor energy bills for signs of sudden jumps in energy consumption.
  • Schedule HVAC tune-ups for spring and fall.

FAQs 

Why is my AC running but not cooling the house?

If you have an AC that is not blowing cold air, a few issues may be going on. You could have a dirty filter, frozen evaporator coils, a faulty thermostat, low refrigerant levels, or blocked condenser coils. You can troubleshoot by resetting your thermostat, changing the air filter, and cleaning the condenser coils. However, if this problem keeps recurring, you should get professional help.

How often should I replace filters?

Ideally, air filters should be replaced every one to three months. You should check with your manufacturer’s directions to see if they have any specifications. Additionally, you should change the filter more frequently if you have a particularly dusty home or are using your AC more frequently.

Can I add refrigerant myself?

No, you can’t. The United States has specific laws about who can handle refrigerants. HVAC technicians are required to be federally certified, so this isn’t something that can be done by a homeowner.

Why does my AC freeze up?

Anything that decreases the airflow or reduces refrigerant levels can cause your AC to freeze. Before troubleshooting, you should let the evaporator coils thaw completely. Then, change your air filter and make sure all of the vents are open. If your AC continues to freeze, you may have a faulty blower motor, dirty evaporator coils, or a similar problem that requires professional AC repairs.

Why is my AC blowing warm air only in one room?

If you have an AC that is not cooling but blowing warm air in one room, it may be related to ductwork issues or closed vents. However, it could also be related to how your system is set up. If the thermostat sensors are in an especially cold area or the room is the farthest from the AC, it may not be getting as cold as the rest of the system. A complete HVAC inspection can help you figure out what’s going on.

How much does AC repair cost on average?

The cost of AC repairs depends on what is wrong with it. While the overall cost range is between $130 and $2,000, different parts have different repair and replacement costs. For example, a circuit board costs between $100 and $600. A compressor can cost between $800 and $3,000.

What’s cheaper long term: repair or replace?

It depends on the type of problems you’re experiencing and the age of your system. If repair costs are less than half the cost of a replacement or the AC is less than 10 years old, it likely makes more sense to simply repair it.

Why does my AC leak water inside?

If your AC is leaking water on the inside, a few things could be going on. There are three essential reasons why this may happen. If low refrigerant levels or a dirty filter cause your evaporator coils to freeze, you may notice water leaking. Clogged condensate drain lines and damaged drain pans can also lead to leaking water.

Can poor insulation cause my AC to seem weak?

Poor home insulation forces your AC to work harder to reach and maintain the same temperature. While it doesn’t actually weaken your AC, it can eventually lead to increased wear and tear. To avoid more frequent repairs and high energy bills, it’s a good idea to improve your home’s insulation.

How do I know my AC is the wrong size for my home?

There are a few signs your AC’s capacity may be too high or too low.
  • Short cycling or unusually long cycles
  • High humidity 
  • Inexplicably high energy bills
  • Uneven cooling
  • Performance issues

Fix Your AC Repair Issues Today

If your AC unit is not blowing cold air anymore, start by performing DIY checks. You need to call for professional air conditioning repairs if you still have an AC that is not cooling. When it comes to HVAC systems, prevention is always cheaper than emergency repairs. 

At Central Oregon Heating, Cooling, Plumbing & Electrical, we can help with all your AC replacement and repair needs. If you’re still facing issues, schedule an inspection with your local HVAC experts today.

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