Imagine this: it’s the middle of a sweltering Phoenix summer, where temperatures can soar to over 110°F. You’ve been out all day and all you want is to relax in the cool comfort of your home. But when you walk in, instead of a refreshing blast of cold air, you’re greeted by a stuffy, warm interior. You check your air conditioning unit, but it’s running perfectly fine – at least it seems to be. The problem? Your AC isn’t cooling your house.

This is a common issue that homeowners face and it’s incredibly frustrating, especially during the hot summer months. But don’t worry – there are several reasons why your AC may not be cooling, and many of them can be fixed without calling in a professional. In this troubleshooting guide, we will walk you through the common reasons why your AC isn’t cooling and how to fix them. We’ll also provide guidance on when it’s time to call a professional HVAC technician and why regular maintenance is key to preventing these issues. Plus, we’ll introduce you to Merlin’s AC & Plumbing, a reliable and trustworthy company that guarantees satisfaction and offers prompt service and transparent pricing.

So, if you’re sitting in a hot house wondering, “Why is my AC not cooling?” – don’t sweat it. We’re here to help you identify and fix the problem. Let’s dive in.

Understanding How Your AC Works

Picturing your air conditioner as a magical box that spits out cool air on hot summer days is easy. Understanding how it does that is a bit more complex, but essential for troubleshooting when things go wrong. So, let’s take a peek under the hood of your AC system and demystify its cooling process.

The Role of the Condenser Coil

First stop on our journey through your AC system is the condenser coil, an essential component situated in the outdoor unit of your air conditioner. The condenser coil, along with a compressor and a fan, forms a trio that plays a crucial role in cooling your home.

The compressor, often referred to as the ‘heart’ of the AC, circulates refrigerant throughout the system. It compresses the refrigerant, increasing its pressure before sending it through the condenser coil. The refrigerant, carrying the heat from your home, releases this heat as it flows through the condenser coil. The fan assists by sending atmospheric air over the coil, further cooling the refrigerant. Remember, the main function of your air conditioner is not to add cool air into your home, but to remove the hot air.

The Importance of the Evaporator Coil

Now let’s venture indoors to the evaporator coil, often housed in a furnace or inside a fan coil cabinet. This is where the magic of heat transfer really happens.

The evaporator coil’s job is to allow the refrigerant, now a cool low-pressure gas after its journey through the condenser coil, to absorb heat from the indoor air. As warm indoor air passes over the cold evaporator coil, the refrigerant inside the coil absorbs the heat, causing the refrigerant to evaporate while simultaneously cooling the air. This cooled air is then circulated back into your home, giving you the relief you need from the Arizona heat.

Both the evaporator and condenser coils are vital to your air conditioner’s cooling process, and understanding their roles can make troubleshooting easier when your AC struggles to cool your home. However, these critical components can encounter issues like dirt buildup or freezing due to improper maintenance or system imbalances, which can significantly impact your AC’s performance. Knowing when and how to address these problems can save you discomfort, time, and money. But more on that later. For now, let’s delve into some common reasons why your AC might not be cooling your home.

Common Reasons Why Your AC Isn’t Cooling

In the desert heat of Phoenix, Arizona, an underperforming air conditioner is more than an inconvenience—it’s a potential health hazard. If your AC isn’t cooling your home as it should, don’t fret. Here’s a list of the usual culprits that might be giving your air conditioner a hard time.

Thermostat Settings

Your thermostat is the control center for your AC unit. If it’s set incorrectly or malfunctioning, your air conditioner might blow warm air or not turn on at all. Check to ensure the thermostat is set to “cool” and at the correct temperature. If your thermostat is set correctly, but your AC still isn’t cooling, it might be time to consider other potential issues.

Clogged Air Filters

A dirty air filter can significantly impact your AC’s performance. The air filter’s role is to catch dirt, dust, and airborne particles, ensuring clean and efficient operation. Over time, these particles accumulate, clogging the filter and restricting airflow. This can lead to reduced cooling and, in extreme cases, can cause the system to shut down completely.

Blocked Condenser Units

The outdoor condenser unit plays a crucial role in expelling heat from your home. If the condenser unit is blocked—by dirt, grass, or other debris—this process is hindered. A clogged condenser unit can lead to reduced energy efficiency, lack of cool air from the registers, or even total system shutdown.

Damaged Heat Pumps

Heat pumps, which can both cool and heat your home, can also be the cause of your AC woes. Similar to an AC unit, a heat pump can suffer from a dirty or clogged coil, refrigerant leaks, and compressor malfunctions that can affect its cooling efficiency.

Frozen Evaporator Coils

A frozen evaporator coil is another common cause of an underperforming AC. The evaporator coil absorbs heat from your home, and if it gets too cold, it can freeze. This might be due to low refrigerant levels, a dirty air filter, or blocked airflow.

Refrigerant Leaks

Refrigerant is essential for absorbing heat from your home and releasing it outside. If there’s a leak, or the system is low on refrigerant, there’s not enough refrigerant to perform this heat transfer effectively. This can cause the evaporator coil to freeze up, leading to warm air or no air blowing from your AC unit.

Undersized AC Units

Lastly, if your air conditioner unit is too small for your home, it might struggle to cool your living space effectively. An undersized AC unit will run constantly, trying to achieve the desired temperature, but it might never quite manage to cool your home to your satisfaction.

Knowing these common reasons why your AC isn’t cooling can help you troubleshoot the problem more effectively. However, remember that attempting to fix complex AC issues yourself might lead to more damage. If in doubt, always call a professional HVAC technician.

How to Troubleshoot Your AC

Nothing is more frustrating than coming home from a scorching day outside only to find your AC unit blowing warm air. Before you throw in the towel and dial up an HVAC technician, try these troubleshooting tips to get your AC back to blowing cool, refreshing air.

Checking the Thermostat Settings

The thermostat is essentially the brain of your AC unit. If it thinks your home is already at the desired temperature, it will tell your AC to stop cooling. To ensure that your thermostat isn’t the culprit, check that it’s set to ‘cool’ and that the temperature is set lower than the current room temperature. If your thermostat requires batteries, replace them with fresh ones. Some newer smart thermostats can also benefit from a hard reset, which involves removing it from its power source and then reconnecting it to allow it to reboot.

Cleaning the Air Filters

Air filters are the gatekeepers for your AC system, trapping dust, dirt, and other pollutants that would otherwise circulate through your home. Unfortunately, they can become clogged over time, reducing the efficiency of your unit and causing it to struggle to cool your home. If your filters are washable, rinse them off with water and let them air dry. If they’re disposable, replace them every three months or as recommended by the manufacturer. Regularly cleaning or replacing your air filters not only improves the efficiency of your AC but also enhances your home’s air quality.

Inspecting the Condenser Units

Condenser units are a crucial part of your AC system, responsible for releasing the heat your AC collects from your home. If your condenser unit is blocked or clogged, it can’t do its job, which can lead to your AC blowing warm air. Inspect your unit for any debris, dirt, or grass that could be obstructing the fins of the coil. If you find any blockages, gently clean them with a vacuum or hose. However, be careful not to damage the delicate fins.

Checking for Refrigerant Leaks

Refrigerant is the lifeblood of your AC system, absorbing heat from your home and releasing it outside. When there’s a leak in the refrigerant line, your AC won’t be able to cool effectively. Signs of a refrigerant leak include warm air coming from the vents, frozen coils, and hissing or bubbling noises. If you suspect a refrigerant leak, it’s best to call in a professional HVAC technician right away, as refrigerant leaks can cause severe damage to your unit if left unaddressed.

Remember, these troubleshooting steps can help you diagnose why your AC isn’t cooling, but they aren’t a replacement for regular professional maintenance. If you’re still struggling with a warm house, don’t hesitate to call a reputable HVAC service provider like Merlin’s AC & Plumbing. Our team of experts is ready to help you beat the heat.

When to Call a Professional HVAC Technician

As much as we’d like to solve all our problems ourselves, sometimes it’s best to call in the experts. When it comes to your air conditioning unit, there are certain situations where a professional HVAC technician can save you time, money, and a lot of unnecessary stress.

Complex Issues with the AC

While simple troubleshooting can often solve minor issues, there are situations where professional help is needed. Problems with your AC compressor, for example, can be incredibly expensive to solve and are best left to a professional. Similarly, if your exterior fan motor is malfunctioning, your AC’s compressor could overheat, leading to more serious issues.

Issues relating to refrigerant leaks are also best left to the professionals. Refrigerant is a vital component of your AC system, responsible for absorbing heat from your indoor air and releasing it outdoors. A lack of refrigerant can severely hamper these heat-transferring abilities and contribute to your AC’s inability to cool your home. If you notice signs of a refrigerant leak, such as ice buildup, decreased cooling, or hissing sounds, it’s time to call in the experts. This is not a do-it-yourself job as it requires special equipment and training to fix.

Preventing Further Damage to the AC

It’s also essential to call an HVAC technician if your AC unit is causing unusually high energy bills or making strange noises. These could be signs of a more serious problem that might lead to significant damage if left unaddressed. A professional can accurately diagnose the cause and prevent further damage to your AC unit, saving you from costly repairs or even a full system replacement in the future.

Additionally, regular maintenance is key to keeping your air conditioning unit in top condition. A professional AC repair service can provide routine maintenance services to ensure that your AC unit is running efficiently and smoothly. This can help extend the life of your air conditioner system and save you money on repairs in the future.

Remember, safety should always come first. Air conditioning systems use electricity and refrigerant, which can be dangerous if not handled properly. Professional air conditioner repair services have the necessary training and equipment to ensure that repairs and maintenance are done safely and correctly.

At Merlin’s AC & Plumbing, we prioritize your comfort and safety. Our team of skilled technicians is ready to help, delivering prompt service and transparent pricing. In the event of an AC emergency, or if you’re simply in need of routine maintenance, don’t hesitate to reach out to us. We’re here to ensure your home stays cool and comfortable, no matter what the Arizona sun has in store.

AC maintenance

The Importance of Regular AC Maintenance

When you’re up against the sweltering Phoenix heat, a well-functioning AC unit is your best ally. But just like any other crucial home system, your air conditioner needs regular upkeep to ensure it runs smoothly when you need it the most. This is where regular AC maintenance comes into play.

Ensuring Optimal Performance

Regular AC maintenance is not just about preventing breakdowns. It’s about optimizing your air conditioner’s performance to create a cool, comfortable environment in your home. A well-maintained AC unit runs more efficiently, saving you money on energy bills and reducing the risk of unexpected repair costs.

During a routine maintenance visit, a professional technician will check your AC unit for any signs of wear and tear, clean the necessary parts, and make any necessary adjustments. This includes evaluating the air flow, checking the refrigerant levels, and assessing each mechanical component. Such a comprehensive inspection ensures your AC system is running at its peak performance, reducing energy consumption and extending the lifespan of your unit.

Preventing Common AC Problems

One of the main reasons why an AC might not be cooling effectively is due to common problems that could have been prevented with regular maintenance. These include issues like a clogged air filter, a dirty condenser coil, a low refrigerant level, or a malfunctioning fan motor.

Regular maintenance can help spot these issues before they escalate into more significant problems. For instance, during a routine check-up, a technician might identify a minor refrigerant leak that, if left untreated, could lead to your AC unit not cooling at all.

Furthermore, regular AC maintenance can also help prevent more catastrophic damages that can be expensive to fix, like compressor failure. By keeping an eye on the overall health of your AC system, a professional can help you avoid these costly repairs and ensure your unit continues to work efficiently.

In conclusion, regular AC maintenance is crucial in ensuring optimal performance of your unit and preventing common AC problems. It’s a small investment that can save you time, money, and the discomfort of a hot, stuffy home during the peak of summer. Don’t wait for your AC to breakdown to call a professional. Schedule your routine maintenance with Merlin’s AC & Plumbing today to keep your home cool and comfortable all summer long.

Why Choose Merlin’s AC & Plumbing

When you’re dealing with an AC unit that’s not cooling your home as it should, you need a reliable and efficient service to turn to. That’s where Merlin’s AC & Plumbing steps in. Offering a range of HVAC and plumbing services, Merlin’s has become a trusted name in the Phoenix, AZ area for several key reasons.

Same-Day Service

There’s nothing more frustrating than waiting for days on end to have your AC issues resolved, especially during a sweltering Phoenix summer. Merlin’s AC & Plumbing prides itself on offering same-day service to attend to your needs promptly. We understand the urgency of a malfunctioning AC and how it can disrupt your comfort. We strive to provide fast and efficient solutions to get your AC unit up and running again in no time.

Upfront Pricing

Nobody likes hidden costs or surprise fees, which is why Merlin’s AC & Plumbing provides upfront pricing. We believe in transparency and honesty in all our dealings. Before we start any work, we provide a detailed quotation so you know exactly what you’re paying for. No hidden charges, no unnecessary add-ons, just a fair price for top-quality service.

100% Satisfaction Guarantee

At Merlin’s AC & Plumbing, our customers are our top priority. We’re not satisfied until you are. That’s why we offer a 100% satisfaction guarantee on all our services. Our team of trained and experienced technicians will work tirelessly to ensure that your AC unit is functioning optimally and efficiently. If for any reason you’re not happy with the service you receive, we pledge to make it right.

Choosing Merlin’s AC & Plumbing means choosing a company that values your comfort and satisfaction. With our same-day service, upfront pricing, and satisfaction guarantee, we’re committed to providing the highest level of customer service. Trust us to keep your home cool and comfortable throughout the Phoenix summer.


As we wrap up this troubleshooting guide, it’s essential to remember that maintaining a cool and comfortable home goes beyond just fixing immediate issues. Understanding how your air conditioning system works and learning to identify common problems can significantly enhance your home’s comfort and potentially save you from expensive repairs.

Throughout this guide, we’ve walked you through the intricate workings of your AC system, highlighting the roles of key components like the condenser coil and evaporator coil. We’ve also discussed common reasons why your AC might not be cooling, from incorrect thermostat settings and clogged air filters to blocked condenser units and refrigerant leaks.

We’ve offered tips on how to troubleshoot your AC, including checking the thermostat settings, cleaning air filters, inspecting the condenser units, and checking for refrigerant leaks. However, when these issues become too complex or if you want to prevent further damage to your AC unit, it’s always best to call in a professional HVAC technician.

Regular AC maintenance is crucial in ensuring optimal performance and preventing common AC problems. By scheduling routine check-ups, you can keep your AC unit in peak condition and extend its lifespan, saving you money in the long run.

At Merlin’s AC & Plumbing, we’re dedicated to providing top-notch service to Phoenix homeowners. Our same-day service, upfront pricing, and 100% satisfaction guarantee mean you can trust us to handle your air conditioning and heating needs promptly and professionally.

In conclusion, don’t let a malfunctioning AC unit get you hot and bothered. With this comprehensive guide, you’re now well-equipped to troubleshoot and fix common AC issues. And when things get too hot to handle, remember that Merlin’s AC & Plumbing is just a call away. Here’s to a cool and comfortable home, all summer long!

Leave a Reply

Your email address will not be published. Required fields are marked *