5 Most Common A/C Failures


In today’s fast-paced world, we rely heavily on technology to make our lives more comfortable, and one of the most crucial technological innovations is air conditioning (A/C). Whether it’s a scorching summer day or a humid night, A/C systems keep us cool and comfortable. However, like any man-made system, A/C units are prone to failures, which can be frustrating and inconvenient. In this comprehensive guide, we’ll explore the five most common A/C failures that homeowners encounter and provide practical solutions to overcome these challenges.

1. Refrigerant Leaks

Refrigerant is the lifeblood of an A/C system, responsible for absorbing and releasing heat to cool the air. A common issue that A/C units face is refrigerant leaks. These leaks can occur due to various reasons, such as corrosion, faulty connections, or manufacturing defects. As refrigerant levels drop, the A/C’s cooling efficiency reduces, resulting in warmer indoor temperatures.

Signs of Refrigerant Leaks

  • Insufficient cooling: If you notice that your A/C isn’t cooling the room as effectively as before, it might indicate a refrigerant leak.
  • Hissing sounds: A noticeable hissing sound near the A/C unit could indicate a refrigerant leak.
  • Frozen evaporator coil: Low refrigerant levels can lead to the evaporator coil freezing over.


When facing a refrigerant leak, it’s essential to enlist the help of a professional HVAC technician. They will first identify the leak’s source and then repair it before recharging the system with the right amount of refrigerant. DIY attempts to fix refrigerant leaks are not recommended, as they often lead to more significant issues.

2. Compressor Failure

The compressor is the heart of an A/C system, responsible for pressurizing and circulating refrigerant. When the compressor fails, the entire cooling process comes to a halt, leaving you with a sweltering environment.

Signs of Compressor Failure

  • Warm air blowing from vents: If the A/C is running, but warm air is coming out of the vents, it could be due to compressor failure.
  • Loud noises: Unusual and loud noises, like clanking or grinding, may indicate a failing compressor.


Replacing a faulty compressor is a complex task best left to trained professionals. Attempting to fix or replace the compressor without proper knowledge and tools can cause further damage to the A/C unit. Contact a reputable HVAC technician to diagnose the issue and provide a suitable replacement if necessary.

3. Frozen Evaporator Coil

The evaporator coil is responsible for absorbing heat from the indoor air to cool it down. However, if the coil becomes too cold, it can freeze over, obstructing proper airflow and hindering the cooling process.

Signs of Frozen Evaporator Coil

  • Reduced airflow: If you notice weak or limited airflow from the A/C vents, it might be due to a frozen evaporator coil.
  • Warm air blowing: Although counterintuitive, a frozen coil can cause the A/C to blow warm air.


If you suspect a frozen evaporator coil, turn off the A/C and let it thaw completely. This may take a few hours. Once thawed, check the air filter and ensure it’s clean. Dirty air filters can cause the coil to freeze. If the issue persists, consult an HVAC technician to identify and address the root cause.

4. Faulty Capacitors

A/C units use capacitors to store and supply electrical energy to different components. Over time, these capacitors can degrade or fail, leading to various A/C malfunctions.

Signs of Faulty Capacitors

  • A/C won’t start: Failed capacitors can prevent the A/C unit from starting altogether.
  • Frequent on-off cycling: If the A/C turns on and off rapidly and repeatedly, it could be due to faulty capacitors.


Replacing capacitors requires technical expertise, and attempting to do it yourself can be hazardous. Call a professional HVAC technician to diagnose the problem accurately and install suitable replacement capacitors.

5. Sensor Problems

Modern A/C units use sensors to detect room temperature and adjust cooling accordingly. When these sensors malfunction, it can lead to temperature inconsistencies and discomfort.

Signs of Sensor Problems

  • A/C short-cycling: Rapid and frequent on-off cycles can result from sensor issues.
  • Incorrect temperature readings: If you suspect that the A/C isn’t cooling your space properly, sensor problems might be the cause.


A trained HVAC technician can recalibrate or replace faulty sensors to restore proper functionality to your A/C system. Regular maintenance and cleaning of the sensors can also help prevent issues in the first place.

Regular Maintenance is Key

A well-functioning A/C system is essential for maintaining a comfortable living environment, especially during hot and humid days. By being aware of the common A/C failures and their signs, you can take prompt action to address these issues. Remember always to consult a professional HVAC technician for repairs and replacements to ensure the safety and efficiency of your A/C unit.

Don’t let A/C failures disrupt your comfort. Keep an eye out for signs of refrigerant leaks, compressor failure, frozen evaporator coils, faulty capacitors, and sensor problems. Regular maintenance and timely repairs will help your A/C system perform at its best and provide you with cool and refreshing air whenever you need it.

Why Choose ROX Heating & Air?

At ROX Heating & Air, we pride ourselves on being the leading experts in HVAC services, including air conditioning repairs and maintenance. Choosing us means choosing excellence, reliability, and top-notch customer service. Here’s why you should trust us with all your A/C needs:

  1. Experience and Expertise: With years of experience in the industry, our team of skilled technicians possesses in-depth knowledge of A/C systems. We have successfully tackled various A/C issues, from refrigerant leaks to compressor failures, providing effective solutions every time.
  2. Prompt and Professional Service: We understand the importance of a well-functioning A/C system, especially during scorching summer days. That’s why we prioritize prompt service, ensuring that your A/C problems are addressed swiftly and efficiently.
  3. Quality Repairs and Replacements: Our commitment to quality is unwavering. When you choose ROX Heating & Air, you can rest assured that all repairs and replacements are carried out using high-quality parts and equipment, ensuring the longevity and performance of your A/C unit.
  4. Transparent Pricing: No hidden fees or surprises when you choose us. We believe in transparent pricing, providing detailed quotes before commencing any work. You’ll know exactly what to expect, so there are no unpleasant surprises later.
  5. Customer Satisfaction: Our ultimate goal is customer satisfaction. We go the extra mile to ensure that our clients are happy with our services. Our team is friendly, approachable, and always ready to assist you with any questions or concerns.

Sign Up for the Priority Comfort Club

At ROX Heating & Air, we value our customers and strive to provide them with the best possible experience. That’s why we offer the Priority Comfort Club – an exclusive membership program designed to enhance your A/C system’s performance and extend its lifespan.

Benefits of Joining the Priority Comfort Club:

  1. Priority Scheduling: As a member, you’ll receive priority scheduling for all your HVAC service needs. When you need assistance, you’ll jump to the top of our list, ensuring you get the attention you deserve when you need it most.
  2. Regular Maintenance: Proper maintenance is key to keeping your A/C system running efficiently. Club members receive scheduled maintenance visits, during which our technicians will inspect, clean, and tune up your system, preventing potential issues and optimizing its performance.
  3. Exclusive Discounts: Enjoy special discounts and offers exclusively available to Priority Comfort Club members. From repairs to replacements and other services, you’ll save on various HVAC needs throughout the year.
  4. Extended Warranty: Your membership comes with additional warranty coverage on repairs and replacements. Experience peace of mind knowing that your A/C system is protected beyond the standard warranty period.
  5. 24/7 Emergency Service: A/C emergencies can happen at any time, and as a Priority Comfort Club member, you’ll have access to our 24/7 emergency service. You can count on us to be there when you need us most, even during weekends and holidays.


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Priority Comfort Club

Become a member and enjoy the benefits of regular HVAC maintenance, including exclusive discounts, priority service scheduling, annual HVAC Maintenance, and peace of mind.  Colorado's Best HVAC Maintenance Membership Program.

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