AC Compressor Not Working? Troubleshooting Steps and Common Causes

When temperatures start to rise in Northern Colorado, the last thing you want is to have your AC compressor not working. Often, an AC compressor will fail if there is a problem with the capacitor, refrigerant level, or electrical system. While you can troubleshoot some of these problems on your own, others must be handled by a professional heating, ventilation, and air conditioning (HVAC) technician for the safety of your home and family.

To learn more about common causes of compressor issues and how Balance Point Heating, Cooling & Plumbing can help, read on.

What Homeowners Usually Mean by a “Compressor Not Working” 

When we get a call that an AC compressor is not turning on, it’s normally because a homeowner noticed a few common symptoms. For example, humming noises without any cooling, clicking sounds, tripped breakers after the cooling cycle starts, and silent outdoor units are common when an AC compressor isn’t working.

However, these issues can also be due to other problems. A capacitor malfunction can keep the cooling cycle from turning on, and low refrigerant levels can result in poor performance. Because of the many potential causes involved, it’s essential to get a professional diagnosis.

Safe First Checks Before You Call 

Before you call for help, there are a few troubleshooting steps you can safely perform on your own.

Check 1: Confirm Your Thermostat Settings

If the thermostat isn’t in “Cool” mode or the temperature is higher than your room temperature, your AC won’t kick on.

Check 2: Inspect the Air Filter 

Check your air filter to see if it is clogged. Ideally, your air filter should be changed every 30 to 90 days as part of your routine maintenance. 

Check 3: Check Your Breaker 

A tripped breaker can keep your outdoor unit from switching on. Check your breaker and reset it once. If it trips again, don’t switch it on because there’s an underlying electrical problem that needs to be handled by a professional.

Check 4: Look at the Condenser

Look at your condenser to see if there is any obvious debris or damage. 

Check 5: Listen for Unusual Sounds

If you notice that the AC compressor clicks, then stops, produces humming sounds, or shuts down immediately after starting, note the sounds. This information will help your HVAC technician narrow down the potential causes.

For your safety, you should never open panels, attempt DIY electrical repairs, or keep resetting the breaker. Our team can safely diagnose the problem and help you determine whether an AC replacement or repair will be necessary.

Symptom-by-Symptom Troubleshooting for Compressor-Related Breakdowns

When your AC compressor is not working, there are a few common issues that could be at fault. With Loveland AC not cooling troubleshooting, you can get a better idea about what is going on.

Unit Won’t Start at All

If your Fort Collins AC compressor is not starting at all, it is likely due to a problem with your capacitor, contactor, thermostat signal, breaker, or wiring. These problems can be quickly diagnosed and repaired by calling our team for help.

The Fan Runs, but the System Won’t Cool

If this symptom occurs, you are likely dealing with a strained compressor or refrigerant-related issue. For example, low refrigerant levels can keep the unit from cooling properly. If there is a control problem, this can also prevent the unit from cooling to the temperature you want.

Clicking and Humming Sounds

When your outdoor unit is humming and not cooling, you likely have a problem with your electrical system or a startup component. To avoid further damage, you should turn off your unit and call for help.

Breaker Trips When Cooling Begins

If you are dealing with a compressor breaker that keeps tripping, AC compressor strain, an electrical overload, or a shorted component is likely at fault. Because of the safety issues involved, a licensed technician must address all of these problems.

Most Common Causes of Compressor Problems We See in the Field 

When we get called out for suspected compressor issues, there are a few common issues that we typically diagnose. While older units may experience true compressor failure, there are often other repair issues that are causing the temporary decline in compressor performance.

• Failed capacitors or contactors
• Refrigerant-related strain
• Dirty coils
• Restricted airflow
• Electrical panel, component, or disconnect issues
• True compressor failure in older ACs 

No matter what the cause, our team can quickly diagnose the issue. When summer temperatures rise in Fort Collins and Loveland, you can’t afford to go without AC for long. Through our 100% no-interest financing, you can get help budgeting for your next repair or replacement.

When To Shut the System Off and Call Right Away 

While there are problems you can troubleshoot on your own, you should never attempt repairs when the following symptoms are involved. Instead, you should switch off the AC and call for help immediately.

• The breaker keeps tripping repeatedly.
• Your home has vulnerable family members who can’t safely handle high heat.
• There are loud metallic noises or severe humming sounds with no cooling.
• You smell something burning or notice visible electrical damage.

For a full explanation of potential warning signs, causes, and repair-vs-replace decision-making tips, check out our full compressor guide.

Frequently Asked Questions 

Does this always mean the compressor itself is bad? 

Not necessarily. Many symptoms of capacitor, thermostat, breaker, and contactor issues will look like a compressor problem at first.

Should I keep resetting the breaker? 

If you reset your breaker and it immediately trips again, leave it off. This indicates an underlying electrical issue that needs to be diagnosed and repaired by a professional. Before you turn it on again, schedule a professional HVAC service appointment.

Solve Your Compressor Issues

Struggling with an AC compressor not working or poor cooling performance? Balance Point Heating, Cooling & Plumbing offers same-day diagnostics and upfront pricing in the Fort Collins and Loveland area. Through our membership plan, you can also get complimentary tune-ups and prevent future breakdowns.

We will diagnose the cause, explain your options clearly, and provide no-pressure solutions for your next step. Learn more by contacting our team today.