Common Reasons Why Your AC Compressor Is Not Turning On & What To Do

Has your air conditioner suddenly stopped working? A faulty AC compressor could be to blame. The compressor is the heart of your AC system, helping circulate cooled air throughout your home. If the compressor isn’t working, your air conditioner may not turn on or will only blow warm air. 

At Total Comfort, we know how frustrating it is when your AC is not performing as it should. That’s why we’re here to help. In this guide, we will walk you through the most common signs of a failing AC compressor, so you’ll know when it’s time to call in our expert team. 

Acting early can prevent further damage and restore comfort to your home quickly. 

12 Reasons Why Your AC Compressor Is Not Turning On

1. Improper Refrigerant Charge

AC refrigerant is responsible for absorbing and releasing heat in your AC system. When refrigerant levels are low, the unit has to work overtime to cool your home, leading to a significant spike in energy costs and an increased chance of repairs or breakdowns. 

It’s best to catch and fix refrigerant leaks early to avoid significant damage. Here are a few signs of a refrigerant leak:

1. Vents are blowing less cold air. 
2. Your home takes longer to cool.
3. You hear unusual noises coming from the refrigerant line. 

2. Power Issues

If your air conditioner won’t turn on, check to ensure your power is working properly. Inspect your panel for a blown fuse or a tripped breaker. It’s common for fuse boxes to label the fuse or breaker connected to your AC unit, so it’s easier to locate. 

If you see that the breaker is switched to the off position, simply switch it back on to restore power to your AC unit. However, if a fuse is blown, you will need to replace it. 

It’s best to check your breaker box immediately after any power outage to ensure the quickest restoration and minimal disruption to your cooling system.

3. Burnt or Damaged Wires

Just like the rest of your AC system, the electrical wiring connected to the AC compressor can become overworked. This results in overheated, burnt, and damaged wires that cause compressor failures and even safety hazards. 

Check for burnt or damaged wires by first turning off the power to the unit for safety. Look for visible signs such as melted insulation, burnt smells, or exposed copper. 

If the damage is limited and has not affected the compressor or other components, a licensed technician can replace the wires. However, if the damage is extensive, it might indicate a larger issue that could require a full AC unit replacement. 

4. Capacitors Not Working Properly

The capacitor supplies the required power to the AC unit’s motors and compressor, initiating the cooling cycle. When capacitors fail, they cause compressor malfunctions and disrupt home cooling. 

Checking for a properly working capacitor is a lengthy and complicated process, so it is best left to professional technicians. 

If you suspect that your capacitor is broken, contact the team at Total Comfort for professional assistance. We have the tools to accurately measure the current and voltage, allowing us to determine whether you need to replace the capacitor. 

5. Contaminated Refrigerant

When contaminants, such as dirt, debris, and oil, enter the refrigerant, they can cause your AC to stop working by creating blockages and reducing the compressor’s heat transfer ability. 

Refrigerant contamination is preventable with routine maintenance and inspection that address issues before they escalate. Common causes of contamination include improper handling, incorrect or mixed refrigerant types, and system leaks that result in excess moisture and air buildup. 

6. Dirt Buildup in the Compressor

Dirt buildup naturally occurs in the AC compressor with usage and age. However, without proper maintenance and a thorough cleaning, dirt and grime can cause damaging blockages, stopping the AC compressor from turning on. Dirt particles in your AC unit also contaminate the air quality in your home and lead to health issues. 

Yearly maintenance and cleaning from a professional HVAC technician will help keep your unit clean and running optimally, extend its lifespan, and keep your family healthy. 

7. Expansion Valve Issues

During the cooling cycle, the AC system converts its liquid refrigerant to vapor, which is released to cool and dehumidify your home for a comfortable environment. The system’s expansion valve is an important component in this process. 

However, an expansion valve can break due to AC compressor failure or an excessive refrigerant flow in the AC unit. If the valve malfunctions, you may notice:

• A constantly running AC unit
• Frozen coils 
• The AC compressor fails to turn off
• Unusual noises coming from the AC unit
• Inconsistent airflow through vents 
• Decreased performance of the AC unit 
• Warm air is blowing through vents 

As soon as you notice any of these issues, contact a professional technician for quick repair. They can expertly inspect refrigerant levels and add extra freon to restore normal levels and functioning. 

8. Loose or Disconnected Terminal Connector Parts

The terminal connector is a crucial component that links your AC compressor to the electrical system. If these connectors become loose or disconnected, the compressor won’t receive the power it needs to function. 

You can spot this issue by carefully inspecting the wiring around the AC compressor. Look for any terminals that appear loose, corroded, or disconnected. If you notice anything loose or disconnected, it’s best to call a qualified professional to safely reattach and replace the connectors. 

9. Incorrectly Sized Components

If your AC has stopped working or the AC compressor is not turning on, an improperly sized suction line could be the issue. When suction lines are too short or too long, increased pressure builds in the system, which causes it to overheat. 

Hiring a reliable HVAC technician is crucial to ensuring your AC compressor is installed with correctly sized components. Whether you need the current suction line repaired or a new AC installed, contact our team. Total Comfort technicians know the types of suction lines suitable for different AC unit types and will install them accurately to ensure a well-performing unit. 

10. Dirty Air Filters

Clogged or dirty air filters restrict airflow, forcing your AC system and AC compressor to work harder to maintain the desired temperature. Over time, this extra strain can cause the AC compressor to overheat or fail altogether. 

To prevent this, have your air filters professionally inspected monthly and replaced every 1 to 3 months. The exact timeline depends on your specific usage and filter type; however, regular maintenance can significantly extend the life of your compressor, thereby improving the overall efficiency of your AC system. 

11. Condenser Fan Problems

The condenser fan plays a key role in the AC system’s cooling abilities by dispersing heat from the condenser coils. When the fan isn’t working properly, heat builds up, leading to AC compressor failure and overheating. 

Common reasons for condenser fan problems are a faulty motor, damaged fan blades, or electrical issues. If the fan doesn’t spin or makes strange noises, shut the system off and call a professional for inspection to determine and conduct any needed repairs to the fan blades, motor, or electrical wiring.  

12. Thermostat Malfunctions

Your thermostat is the command center for temperature regulation, cooling, and heating in your system. If it malfunctions, it can prevent the AC compressor from turning on, signifying that the system is no longer working. 

Dead batteries, miscalibration, faulty wiring, or age often cause thermostat malfunctions. If you suspect a broken thermostat or are unable to adequately control the temperature in your home, first check the power source and settings, and reset the device or replace the batteries if necessary. 

If problems persist, you may need a replacement. Reach out to the professionals at Total Comfort for an expert inspection and replacement service. 

When Should I Contact a Professional?

When you’re faced with an AC compressor not turning on, it quickly compromises your comfort and safety. It can also be quite overwhelming to know how to proceed—do you attempt DIY inspection and repair, or call in a professional? 

Total Comfort knows that it can be difficult to decide when to make this call. But if the issue is serious enough to warrant professional help, failing to get it can lead to problems worsening, extending to safety, comfort, and cost complications.

If you’re experiencing ongoing issues or any of the following signs, it’s time to get expert help. Total Comfort offers reliable AC tune-ups, AC replacement, and AC repair. 

AC Won’t Stop Blowing Warm Air

If your AC system is not blowing cold air, it’s a sign of a deeper issue, such as a failing AC compressor, low refrigerant levels, or electrical problems. These mechanical failures require professional tools and expertise to diagnose and repair safely and accurately. 

Compressor Won’t Turn On

An AC compressor not turning on could signal anything from electrical faults to serious internal damage in the AC system. Due to their complexity and importance to your AC system, it’s best to seek a professional inspection to repair the issue and avoid further system damage. 

Unusual Noises

Grinding, banging, or buzzing noises coming from your AC can point to serious issues like loose components, motor problems, or compressor failure. Ignoring these sounds can lead to more extensive and expensive damage, so it’s wise to call a professional technician right away. 

Refrigerant Leaks

Refrigerant leaks are hazardous to both your AC system and your health. They reduce cooling efficiency, cause long-term damage to the AC compressor, and also contaminate your air quality and health. Only a licensed technician can properly locate and repair leaks to safely recharge the system. 

Vibrating or Shaking Unit

An AC unit that shakes or vibrates excessively likely has loose components, a misplaced fan, or mounting issues. These deformations cause movement that leads to damage to internal parts. So, it’s essential to have a professional examine and secure the unit’s components for smooth operation. 

High Energy Bills

A sudden surge in your energy bills often indicates that your AC is working harder than it should. This is likely due to a failing AC compressor, clogged filters, or refrigerant problems. A professional inspection can pinpoint the source of inefficiency and help reduce ongoing maintenance and repair costs. 

Think You Need Your AC Compressor Looked At or Replaced?

If you’re experiencing a gap in cooling or comfort in your home, it may be due to an improperly working AC compressor, which requires immediate and effective professional attention. 

While AC issues often happen unexpectedly, it’s important to stay ahead of them, ensure your AC compressor is working optimally, and know when to call in professional help. 

Total Comfort is the company to call when your AC compressor malfunctions or other system issues arise. Our team knows what it takes to deliver honest, quality work and is deeply committed to customer satisfaction. 

Trust our emergency air conditioning repair services to restore your comfort with skill and compassion every time.