How to Troubleshoot Common Air Conditioner Problems

A cool house is necessary in the Southeast’s hot, humid weather. And when your air conditioner (AC) starts acting up, you want to resolve the issue as soon as possible to keep your home and your family comfortable. 

You can diagnose the issue and resolve more minor problems yourself, but some will require professional help. Here are some basic solutions for the most common issues homeowners experience with their air conditioners.

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Table of Contents

• Common Air Conditioner Problems
  • AC Won’t Turn On
  • AC is Not Blowing Cold Air
  • AC is Making Strange Noises
  • AC Turns On/Off Repeatedly
  • AC Smells Bad
  • Uneven Home Temperature
  • AC is Constantly Running
  • AC Unit Has Ice
  • Problems With Outdoor Compressor
  • When is it Time to Call a Professional?

1. Your AC Won’t Turn On

If you try to start your AC, but it’s not working, you may be dealing with one of the following issues: 

• Thermostat malfunctions: A dead or malfunctioning thermostat will prevent the AC from turning on.
• Interrupted circuit: If the power to the AC gets turned off, you may find the thermostat works, but your AC unit does not.
• Loose wiring: Electrical issues within the AC unit can cause it to stop working entirely. 

Troubleshooting Steps

Try following these steps to see if you can solve the problem:

1. Check thermostat batteries: Take out the batteries and test them by placing them in another device. Replace them if they’re dead.
2. Inspect circuit breakers: If the thermostat is working but your AC unit is not, check your circuit box to see if the breaker got tripped. Flip the switch off and back on to reset it if needed.
3. Call a technician: If you try both of the above steps and the issue is still happening, call a professional air conditioning technician to check your unit’s wiring.

2. Your AC is Not Blowing Cold Air

If you notice that your air conditioner is blowing room temperature, warm or hot air, there are a few steps you can take to diagnose the issue’s source.

Some of the reasons your AC is blowing warm air may include:

• Clogged or dirty filters: Blocked filters prevent air from flowing into a room, resulting in a lack of cooling.
• Low refrigerant: The refrigerant is the chemical responsible for removing heat from the air, so low levels can cause warm air to blow out of your AC. You may also see ice or condensation forming on the unit’s exterior.
• Thermostat issues: If your thermostat is on the wrong setting, it can cause the AC to blow warmer air than you need.
• Tripped circuit breaker: Your AC won’t blow any air until you restore the power source.

Troubleshooting Steps

Here are some steps you can take to solve the problem:

• Open and unblock your return vents.
• Clean or change your filters. 
• Make sure to set your thermostat to the correct temperature.
• Check the circuit breaker to see if it tripped.
• Check around your AC unit and in your condensate pan for leaks.
• Find out if the outdoor unit is still on. 

Air conditioner still blowing hot air into your home? Call a professional service provider for additional help.  

3. Your AC Is Making Strange Noises

You may be dealing with a more serious issue if you hear your AC unit making abnormal sounds. Some common examples include:

• Clicking: If you hear clicking when you turn your AC unit on and off, the relay could be malfunctioning.
• Hissing: Your refrigerant lines are likely leaking. 
• Screeching: The unit’s compressor or fan motor is possibly breaking down.
• Thumping, banging or rattling: The blower or motor assembly may be damaged or worn.
• Buzzing: Electrical components in your AC may be malfunctioning.
• Scraping or grinding: Your belt may be worn or out of place, and you may also smell burning rubber. 

Troubleshooting Steps

Scheduling a maintenance appointment is often the best first step for dealing with these noises. Your tech can identify the source and solve the issue or determine whether you need more extensive repairs. 

The sooner you have a professional inspect your unit, the better. They can ensure problems don’t escalate and your AC is in good working condition for reliable use. 

4. Your AC Turns On and Off Repeatedly

Short cycling happens when your AC unit turns on and off repeatedly, and it’s one of the most common problems homeowners experience. 

Most of the time, this issue results from a malfunctioning thermostat. Some of the issues that can impact your thermostat’s ability to function include:

• Loose screws or wires
• Improper thermostat placement
• Dead batteries

Your AC may also begin short cycling due to a buildup of dust and debris in the unit or a refrigerant leak. With the right tools and expertise, these are entirely manageable issues.

Troubleshooting Steps

First, look at your thermostat’s positioning. Is it exposed to direct sunlight or placed in a particularly warm area in your home? 

Placing your thermostat in an especially warm area will cause it to gauge the incorrect temperature, triggering more frequent cycles in an attempt to cool your home. Moving it to a cooler spot is the easiest solution.

If it’s already in a cool area, check its batteries and replace them if needed. And if nothing else works, call a professional to diagnose and resolve the issue.

5. Your AC Smells Bad

Smelling something strange in your home? The cause could be your air conditioner. Some of the most commonly described AC smells include:

• Stale and musty: Excessive humidity and a lack of maintenance create the perfect conditions for mold and mildew to grow in your air conditioning unit, which can produce a smell like dirty socks.
• Burnt metal: If you smell a sharp, burning metallic scent, the internal wiring of your AC may be burning — this is a serious issue that requires immediate professional intervention.
• Skunk: If you smell something resembling skunk spray coming from your AC, you may be dealing with a gas leak. Leave your home immediately, then call 911 and your gas company to handle the situation.
• Rotten eggs: A strong rotten eggs smell is another potential sign of a gas leak. It can also be coming from an animal trapped in your ducts.
• Sweet and chemical: Refrigerant often gives off a thick, chemical scent. You may have a leaking refrigerant line if you smell something sickly sweet.

Troubleshooting Steps

If you think you smell gas, evacuate immediately and get to a safe place at least 300 feet from your home, ensuring you close the door behind you. Call 911 and your gas provider to report the situation. Otherwise, start by turning the AC off and calling a professional technician to handle the issue.

6. The Temperature in Your Home Is Uneven

The point of central air conditioning is to create a cool, comfortable home. So when you notice certain rooms are warmer than others, you may be dealing with an air conditioner issue. Some of the most common causes of uneven cooling include:

• Clogged filters
• Blocked vents
• Wrong AC size
• Improper installation

While diagnosing this issue is fairly easy, you may need expert help if the cause is more complex.

Troubleshooting Steps

First, replace the filter and make sure nothing is in front of the vents. Vacuum your vents every month to prevent dust and debris from building up and causing additional issues in the future. 

Installation problems are best left to an experienced technician who knows the ins and outs of disassembling and reassembling your AC unit. An in-house consultation is the easiest way to solve this issue.

A professional can also help you determine whether your home’s air conditioner is the wrong size. And if it is, they can recommend potential alternatives to eliminate the issue from coming back in the future.

7. Your AC Is Constantly Running

While it’s normal for your air conditioning unit to run more cycles in hot climates, it needs a break eventually. Letting it run for too long can wear down its internal parts and cause your energy bills to spike. Some of the reasons you may be experiencing this issue include:

• Malfunctioning thermostat
• Compressor issues
• Faulty electrical components
• Clogged air filters

You can usually troubleshoot some of these problems yourself, though you may need extra help if it’s a more complicated issue.

Troubleshooting Steps

First, try turning your thermostat off and back on to see if a hard reset will solve the problem. If it’s still cycling constantly, try changing the air filters with clean ones. 

Finally, if replacing the filters doesn’t work, you’ll want to call an expert air conditioning service provider to diagnose and resolve the issue.

8. You See Ice on the AC Unit

If you notice ice or frost forming on your AC unit, your evaporator coil is likely frozen.  

The evaporator coil contains refrigerant, which is the chemical that absorbs heat from inside your home. When it malfunctions, it can overcompensate to the point where the outside of your unit freezes.

Conditions that can cause a frozen coil include:

• Low refrigerant levels: Refrigerant leaks cause the pressure within the evaporator coils to drop, which makes the coil absorb excess heat. The coils and refrigerant lines will freeze as they rapidly cool to compensate.
• Clogged or dirty air filters: Dirt and debris in your filters can block airflow, preventing the transportation of cold air from the coils back into your home.
• Mechanical issues: Blocked condensate lines, kinks in the refrigerant lines and other component issues can cause the unit to freeze.

Troubleshooting Steps

First, turn the AC off to prevent further ice buildup. In some cases, keeping the unit off will allow the coils to thaw. However, temperatures in the Southeast can be intolerable without air conditioning, and calling a reliable HVAC service provider is the best way to tackle this problem quickly. 

9. Your Outdoor Compressor Is Having Problems

Most air conditioners include an outside unit that releases the heat from your home back into the air. Typically, it should produce a low humming sound — silence or abnormal noises can indicate a serious issue.

If the compressor is on but the fan is not moving, you’re probably dealing with a broken fan motor, a faulty start capacitor or both. When both are malfunctioning, there are two possible causes: 

• Defective compressor contactor
• Insufficient power to the outdoor unit

While you can usually solve one of these issues yourself, more intensive mechanical and electrical issues should always go to an experienced technician.

Troubleshooting Steps

Some possible solutions for this problem include:

• Stuck fan: One temporary fix is manually starting the fan using a long item. However, you’ll want professional help if that doesn’t work.
• Blocked airflow: Check the area surrounding the compressor, and ensure there are at least two feet of space between the compressor and any plants, decorations or outdoor structures.
• Tripped breaker: Check your circuit breakers to confirm that the outdoor unit’s breaker tripped. If it is, turn off your AC at the thermostat to allow it to rest. If not, you may need to call a technician to replace the contactor.

When Is It Time to Call a Professional?

While you can successfully troubleshoot many common AC problems solo, it’s important to call for professional help when you run into any of the following:

• Electrical issues: Attempting to fix electrical problems yourself is dangerous without the proper training and equipment. An experienced professional can handle these issues without putting themselves in harm’s way.
• Refrigerant leaks: Refrigerant is a strong chemical that can cause environmental and physical damage if handled improperly, so leaving this to a pro is the best choice.
• Strange noises: Most of the causes behind strange noises are mechanical issues that require expert attention. 
• Odd smells: You’re likely dealing with a significant issue if you smell burning, rotten eggs or a sweet chemical odor. 
• Major airflow obstructions: If you’ve cleaned or replaced the filter and your AC still has issues, a larger blockage may be inside your unit. A professional can handle this problem for you without causing damage to the unit.
• Returning problems: If you keep having the same issue repeatedly, a professional can help you stop the problem at its source and avoid dealing with extensive, costly damage.

Choose Strada Air Conditioning & Heating for Fast, Friendly Service

When you’re dealing with AC problems, some tasks are better left in the hands of experienced professionals. Strada Air Conditioning & Heating is here for you. Our team will ensure your unit is functioning properly so your family has a cool, comfortable place to escape the heat. 

Count on us for reliable maintenance, repair and replacement services. Our customer service team is highly responsive, and we’ll take great care of your cooling system. 

Schedule an appointment with one of our technicians, and get back to enjoying your home.