What Causes an AC Unit to Break Down?

Your air conditioning (AC) unit is essential to your home, especially during the hot summer months. When it’s working properly, you likely don’t give it much thought. But when it breaks down, the discomfort can be unbearable, and the repair costs can be steep. Understanding the common causes of AC breakdowns can help you take preventive measures to keep your unit running smoothly and extend its lifespan.

In this article, we’ll explore the most common reasons AC units break down, signs to look out for, and tips on how to prevent these issues. By being proactive, you can avoid unexpected breakdowns and costly repairs.

1. Lack of Regular Maintenance

One of the most common reasons for AC breakdowns is a lack of regular maintenance. Like any complex machine, an AC unit requires regular upkeep to function optimally. When maintenance is neglected, small issues can escalate into major problems, leading to system failure.

Common Maintenance Issues:

• Dirty Air Filters: Air filters trap dust, dirt, and other particles, preventing them from entering the AC system. Over time, these filters can become clogged, restricting airflow and causing the unit to work harder than necessary. This added strain can lead to overheating and eventual breakdown.
• Dirty Coils: The evaporator and condenser coils are responsible for absorbing and releasing heat. When these coils become dirty, the AC’s ability to cool the air diminishes, causing the system to run longer and work harder, increasing the risk of a breakdown.
• Low Refrigerant Levels: Refrigerant is the substance that cools the air in your AC unit. If the refrigerant levels are low, either due to a leak or improper maintenance, the unit will struggle to cool your home, leading to potential overheating and failure.

Solution:

Schedule regular maintenance checks with a professional HVAC technician. These checks typically include cleaning or replacing air filters, inspecting and cleaning coils, checking refrigerant levels, and ensuring that all components are functioning correctly. 

Regular maintenance can significantly reduce the risk of unexpected breakdowns and extend the life of your AC unit.

2. Refrigerant Leaks

Refrigerant leaks are another common cause of AC breakdowns. The refrigerant is crucial for the cooling process, and without the proper amount, your AC unit won’t be able to cool your home effectively.

Signs of a Refrigerant Leak:

• Inefficient Cooling: If your AC is running but not cooling your home as it should, it could be due to low refrigerant levels caused by a leak.
• Hissing Sounds: A hissing or bubbling sound coming from your AC unit may indicate a refrigerant leak.
• Frozen Evaporator Coils: Low refrigerant levels can cause the evaporator coils to freeze, leading to poor cooling performance and potential damage to the unit.

Solution:

If you suspect a refrigerant leak, it’s essential to call a professional HVAC technician immediately. A technician can locate the leak, repair it, and recharge the system with the correct amount of refrigerant. It’s important to note that refrigerant leaks are not something you should attempt to fix on your own. Handling refrigerant requires specialized training and equipment.

3. Electrical Issues

Electrical problems are a common cause of AC unit breakdowns and can be particularly tricky to diagnose. These issues can range from faulty wiring to issues with the AC’s electrical components, such as capacitors and relays.

Common Electrical Problems:

• Capacitor Failure: The capacitor is responsible for providing the necessary power to start and run the AC unit. Over time, capacitors can wear out, causing the unit to struggle to start or fail to start altogether.
• Worn-Out Contactor: The contactor is a switch that controls the flow of electricity to the AC unit’s compressor and condenser fan motor. If the contactor becomes worn or damaged, it can prevent the unit from functioning properly.
• Faulty Wiring: Poor or damaged wiring can cause short circuits, power surges, or other electrical issues. These can lead to AC breakdowns.

Solution:

If you experience frequent electrical issues with your AC unit, then it’s important to have a professional HVAC technician inspect the system. They can diagnose and repair any electrical problems, ensuring that your unit operates safely and efficiently.

4. Thermostat Problems

The thermostat is the control center of your AC unit. If it’s not functioning correctly, then it can cause your unit to break down. Common thermostat issues include incorrect calibration, wiring problems, or simply being outdated.

Signs of Thermostat Problems:

• Inconsistent Temperatures: If you notice that some rooms are significantly warmer or cooler than others, it could be due to a faulty thermostat.
• Unresponsive Controls: If your thermostat is not responding to your inputs or is displaying incorrect readings, it may be time to replace it.
• Short Cycling: Short cycling occurs when the AC unit turns on and off frequently, often due to a malfunctioning thermostat. This puts added stress on the system and can lead to a breakdown.

Solution:

If you suspect your thermostat is causing issues with your AC unit, consider upgrading to a programmable or smart thermostat. These modern thermostats offer better accuracy, energy efficiency, and the convenience of controlling your system remotely. A professional HVAC technician can install and calibrate the new thermostat to ensure optimal performance.

5. Clogged Drain Lines

Your AC unit removes moisture from the air as it cools your home, and this moisture is drained away through a condensate drain line. Over time, this drain line can become clogged with dirt, algae, or other debris, leading to water backup and potential damage to the unit.

Signs of a Clogged Drain Line:

• Water Leaks: If you notice water pooling around your AC unit, it could be due to a clogged drain line.
• Musty Odors: A clogged drain line can cause water to back up and create a breeding ground for mold and mildew, leading to unpleasant odors.
• System Shutdown: Some AC units have a safety feature that shuts down the system if the drain line is clogged to prevent water damage.

Solution:

Regular maintenance, including cleaning the drain line, can prevent clogs and water damage. If you suspect a clogged drain line, it’s important to address it promptly to avoid further issues. A professional HVAC technician can clear the clog and ensure that the drain line is functioning properly.

6. Aging Components

Like all mechanical systems, AC units have a finite lifespan. Over time, the components of your AC unit will wear out. Then this can lead to decreased efficiency and an increased likelihood of breakdowns. Most AC units have a lifespan of 10 to 15 years, depending on usage and maintenance.

Signs of Aging Components:

• Frequent Repairs: If your AC unit requires frequent repairs, then it may be a sign that the components are nearing the end of their lifespan.
• Decreased Efficiency: As components wear out, your AC unit may struggle to cool your home effectively, leading to higher energy bills.
• Unusual Noises: Aging components can cause your AC unit to make unusual noises, such as grinding, rattling, or squealing.

Solution:

If your AC unit is more than 10 years old and experiencing frequent issues, then it may be time to consider replacing it with a newer, more energy-efficient model. While the initial cost of a new unit may be significant, the long-term savings on energy bills and reduced repair costs can make it a worthwhile investment.

7. Improper Installation

Improper installation is another common cause of AC breakdowns. If an AC unit is not installed correctly, then it can lead to a range of problems, including poor performance, increased wear and tear, and premature failure.

Common Installation Issues:

• Incorrect Sizing: An AC unit that is too large or too small for your home will struggle to maintain the desired temperature. Then, this can lead to increased energy consumption and potential breakdowns.
• Poor Ductwork: If the ductwork is not properly designed or installed, then it can lead to airflow issues, causing your AC unit to work harder and increasing the risk of a breakdown.
• Refrigerant Problems: If the refrigerant levels are not properly charged during installation, then it can cause the unit to operate inefficiently and eventually break down.

Solution:

To avoid problems caused by improper installation, hire a reputable and experienced HVAC contractor for your AC installation. A professional contractor will ensure that your unit is properly sized, installed, and calibrated to provide optimal performance and efficiency.

8. Overworking the AC Unit

Running your AC unit continuously without giving it a break can cause it to overheat and break down. This is especially true during extremely hot weather when your AC unit is already working hard to keep your home cool.

Signs of Overworking:

• Constant Running: If your AC unit runs continuously without cycling off, then it may be overworked and at risk of breaking down.
• Increased Energy Bills: An overworked AC unit will consume more energy, leading to higher utility bills.
• Reduced Cooling Performance: If your AC unit is struggling to maintain a comfortable temperature, then it may be overworked and in need of maintenance.

Solution:

To prevent overworking your AC unit, consider using a programmable thermostat. They let you set temperature schedules that allow the unit to rest when you’re not at home. Additionally, using ceiling fans, closing curtains, and sealing windows can help reduce the load on your AC unit and improve its efficiency.

Trust Heating and Air is Here to Help with Your Broken AC Unit

Understanding the common causes of a broken AC unit can help you take proactive steps to prevent them and keep your system running smoothly. However, even with regular maintenance and care, AC units can still experience issues from time to time. When that happens, it’s important to have a reliable HVAC service provider you can trust.

At Trust Heating and Air, we specialize in keeping your AC unit in top condition. Whether you need routine maintenance, emergency repairs, or a new system installation, our team of experienced technicians is here to help. We pride ourselves on providing prompt, professional service to ensure your home stays comfortable year-round.

Don’t wait until your AC unit breaks down to take action. Contact Trust Heating and Air today to schedule a maintenance check or learn more about our services. By staying ahead of potential problems, you can enjoy a cool, comfortable home and lower energy bills all summer long.