AC Not Cooling? 10 Troubleshooting Tips For A Broken Air Conditioner

Furnace or Air Handler

5. Ensure that the condensation drip pans and/or drain lines near your furnace or air handler are clear. A clogged HVAC drain line or indoor coil drip pan may trigger the safety float switch, which will shut down your system to protect your home from potential flooding.

6. Also, verify that the door panel on the furnace/air handler is in place and secure; this allows the safety door switch to activate. Sometimes the door shakes loose, which causes the safety switch to shut down the unit.

Dirty Air Filters Restrict Air Flow

7. Confirm that the air filter is clean. A dirty air filter can restrict airflow, causing your air conditioning and heating system to shut down or operate improperly. Your air filter should be replaced every 1 to 3 months, depending on your system and home air quality. For more information about home air filters, read this article about How Often You Should Change Your Home Air Filter.

8. Check that the air intake grills and supply registers are open and unobstructed. Your heating and air conditioning system needs sufficient airflow to work properly. If your “cold air returns” are blocked by furniture or other obstructions, this can affect how well your AC system cools or heats your home.

9. Verify that the pilot light is lit on older furnaces. Today’s furnaces come installed with automatic ignition systems and therefore don’t need to be “lit” like the older units. However, if you are lucky enough to have an older unit with an unlit pilot light, your system has a safety feature that will prevent your furnace from turning on. Note: If you have an older system with a pilot light, you may want to consider upgrading to a newer, safer system. Compare your options with Extreme Comfort’s Instant Quote or contact us to learn more

Outdoor condenser unit/AC unit

Dirty Outdoor AC Coils Restrict Air Flow

10. Verify that the outdoor coil is clean and has unobstructed air flow. Check the AC unit for dirt, debris, or bushes that are blocking airflow. Since your AC unit is constantly pushing cool air over the warm coils, dirty coils or clogged fins can significantly impact the performance of your outdoor condenser (air conditioning unit). If your AC unit is dirty, gently spray the outside of the air conditioner with a hose to rinse the dirt away. Be careful not to use a high-pressure stream of water, which could bend the fins inside your AC unit.

If you want to schedule a quote for a new air conditioning installation in Plano, TX, or surrounding communities, click the link below.

Sometimes, AC system problems can be solved by a professional technician.

Contact an Extreme Comfort professional technician if:

Ice On Outdoor AC Unit

 1. If you see ice on the pipes or near the outdoor condenser-AC unit, this results from something failing with your unit and will continue until the problem is resolved.

2. You hear unusual noises coming from your furnace or AC unit. Just like with your car, something is beginning to fail if your AC unit or furnace makes an odd noise. The sooner you have your air conditioning system serviced, the better.

3. Air flow from your vents is much lower than usual. If you have already checked and confirmed that your air filter is clean and free of debris, then something else is causing the issue.

4. Your AC system is rapidly starting and stopping.

5. If circuit breakers won’t reset or repeatedly trip. Circuit breakers often trip to protect your home, but sometimes they fail. Either way, this issue needs to be addressed immediately.

6. If your home doesn’t feel as cool or warm as you would like. Sometimes this is the result of a failing system; sometimes it is the result of a lack of airflow, which is a much easier issue to solve. Either way, you should have your HVAC system evaluated for efficiency.

7. If you smell something burning. If you smell something burning, turn off your system and call for a service call ASAP.

8. If you smell gas, leave the house immediately and call the gas company.

9. If you see oil accumulating near the air conditioner or piping.

10. If you have higher-than-usual utility bills compared to the recent weather, this is often a sign of a struggling or failing air conditioning unit. It can also be caused by low coolant or Freon levels in your HVAC system. Since Air Conditioning systems are closed, low coolant levels indicate a leak that needs to be addressed immediately.

If your AC System is still not working, let Extreme Comfort Relief solve your problem. Click the link below to schedule an appointment for the quickest AC Repair Service in Plano, TX, or surrounding communities.

AC Not Cooling: Frequently Asked Questions

What should I check first if my AC stops working?
Start with the thermostat. Confirm it has power, the batteries are good, and it’s set to Cool with a temperature below the current room temperature. Many no-cool calls trace back to a simple thermostat setting.

Why does a loose furnace door panel shut off my AC?

Furnaces and air handlers have a safety door switch that disables the system if the panel isn’t fully secured. If the panel shakes loose, the switch shuts the unit down as a safety precaution, even though nothing else is wrong.

Why would a clogged drain line stop my AC from running?

A clogged condensate drain line or a full drip pan can trigger the safety float switch, which shuts the system down to prevent water damage to your home. Clearing the clog typically restores normal operation.

Is it safe to run my AC if I see ice on the outdoor unit?

No. Ice on the outdoor unit or refrigerant lines means something is already failing, such as restricted airflow or low refrigerant. Continuing to run the system can cause further damage, so turn it off and schedule service.

What does it mean if my AC keeps starting and stopping rapidly?

Rapid cycling, also called short cycling, usually points to an electrical, airflow, or refrigerant issue. It puts extra strain on the compressor and should be diagnosed by a technician rather than left to continue.

What should I do if I smell gas or something burning near my AC?

If you smell burning, turn the system off immediately and call for service. If you smell gas, leave the house right away and contact the gas company before calling for HVAC service.

Can a dirty air filter really stop my AC from working?

Yes. A clogged filter restricts airflow enough to cause the system to shut down or run inefficiently. Filters should generally be replaced every 1 to 3 months, depending on usage and air quality.

Why are my utility bills higher even though the weather hasn’t changed much?

A sudden increase in utility bills without a corresponding change in weather often signals a struggling or failing AC system, frequently due to low refrigerant. Since AC systems are sealed, low refrigerant almost always means there’s a leak that needs to be addressed.