Why Is My Air Conditioner Not Turning On?

The short answer is: There are a few reasons why your air conditioner may not be turning on. First, check to make sure that the unit is receiving power by checking the circuit breaker or fuse box. If the unit is receiving power, then the next step is to check the thermostat to make sure it is set to "cool" mode and that the temperature is set below the current room temperature. If the thermostat is set correctly and the unit still isn't turning on, then it is likely that there is an issue with the compressor or another internal component of the air conditioner. In this case, it is best to call a professional for assistance.

AC Not Turning On: What Do I Do?

Is your air conditioner unit not turning on when you need it to? With summer approaching, and the high temperatures throughout the days of summer rising, you don't want to wait and call for emergency air conditioning repair to get your outdoor AC unit fixed. You'll want to know what caused the damage and who you can call to come to repair the unit.

Professional HVAC technicians, like the Comfort Specialists at ARS/Rescue Rooter, have the experience, expertise, and equipment to diagnose your AC system and understand what might be wrong so they can help you get things working again.

There are many reasons why your air conditioner won't turn on. Here are the most common causes related to air conditioners:

1. Circuit Breaker Tripped

When you discover your air conditioning not turning on, it may be as simple as a tripped circuit breaker. This is one of the most common causes, and it can be easily repaired at home. A circuit breaker trips when there's too much high voltage at once. This safety feature can cause your HVAC system to stop working as a precaution.

While you can go to your fuse box and turn the breaker off yourself, this doesn't always resolve the issue. Do not try to flip the switch multiple times if the air conditioning doesn't turn on right away. Do not attempt to flip the breaker if the breaker has tripped frequently. This can indicate a more severe issue that can lead to an electrical fire.

Call a professional HVAC technician to examine the AC unit if you cannot solve the problem.

2. AC Disconnect Shut Off Switch

If your AC won't turn on, you may need to check your outside AC unit disconnect. The outdoor AC disconnect switch sits on your home near your system. It looks like a metal box sitting on the wall of your house. Inside the shut off box sits a pull out head used to complete the circuit of electricity from your main electrical panel to your air conditioner.

If the pull out head has been moved or flipped upside down, it will cut off the power supply to your system leaving it powerless. Simply place the pull out head back into the correct position to ensure a complete circuit is made and power is sent to your system. If the pull out or disconnect are damaged, you will need a heating and air conditioning expert to help you replace the disconnect.

3. Thermostat Issue

If you notice your air conditioner is not turning on when you need it to, take a moment to check your thermostat. Your thermostat not only sets your indoor temperature, but it also tells the AC units when to turn on and blow cold air. Make sure that the thermostat is on and that the screen is lit. If it's turned off, that's a simple fix. Turn it back on to see if it works. Once you turn it on, if it's still not working, you may need to crack it open.

There may be dust and debris that has collected inside the thermostat. These particles can cause your AC unit to malfunction and more complicated issues like corrosion and blown fuses. If you encounter these issues, it's best to contact an HVAC technician to take a look. They are equipped with the tools and knowledge to best handle the situation and repair or replace any damaged parts.

4. Blown Fuse

You may find your cooling system not turning on due to a blown fuse in the unit. These fuses are designed to protect the unit from excess amperage but will wear down over time. Blown fuses need to be replaced quickly, which should correct the issue. However, if the new fuses go out just as quickly or instantly, do not continue to replace them.

If you uncover a problem with fuses, it's best to contact your local HVAC professionals. They can take a look and safely assess the situation. When a fuse blows regularly, it can cause damage to the AC unit from electric shocks. In the worst-case scenarios, a regularly blown fuse can lead to property damage or loss of life.

Don't take chances with electrical problems. Hire a professional, so you don't risk your safety during the repairs.

5. Refrigerant Leak

Another cause for the air conditioner not turning on will be if your refrigerant levels are low. Refrigerant eliminates heat by cooling the air so it can be dispersed through your home. However, if the charge is low, this may not be effective. This is a common issue if the refrigerant is undercharged after installation or there's a leak.

You may be tempted to add more refrigerants, but that's not a solution. The leak cannot be left alone either, as the chemical compound will harm the environment.

Call a professional HVAC technician to do the repairs for the best results. Your AC unit may stop functioning if the refrigerant charge is too high or too low, but a professional can determine the right amount. They can match the refrigerant charge to the manufacturer's specifications so that your unit runs at its optimal performance.

6. Clogged Air Filter

When was the last time you changed the air filters in your unit? If you find your central air not turning on, it may be due to a clogged air filter. No matter what type of AC unit you have, clean air filters are essential for optimal results. The filters regulate airflow circulation through the house. When your system attempts to run using a dirty air filter, the airflow is blocked, which does you no favors.

You can try to clean the filters yourself or contact HVAC technicians to do the work for you. They are best suited to handle the replacement of dirty filters, especially in or after colder months when freezing is a risk. You don't want any water around the coils, so make sure to collect it properly if you choose to do the work yourself. Otherwise, a professional can replace the filters for you and ensure your AC unit is working correctly.

Also Check Out: Are More Expensive HVAC Filters Really Better?

7. AC Unit Capacitor Has Failed

Does your AC unit turn on and off sporadically or not turn on at all? If so, you may have a capacitor that has died. There are two capacitors all AC systems are equipped with: a start capacitor which gives the motor the kick it needs to start running, and a run capacitor to allow the motor to continue running until the set temperature inside has been reached.

The capacitor is highly sensitive to heat, so the outdoor unit is prone to overheating in warmer months. Avoid using the warmest or coldest settings to keep it from overheating. Power outages can cause damage to the device as well from power surges with things come back on. So consider installing a surge protector to prevent future harm.

Never try to replace the capacitor yourself! Leave this repair to professional technicians unless you want to risk a potentially fatal electric shock.

8. Clogged AC Drain Line

Your AC unit is not only responsible for the heating or cooling of your home but also for removing moisture from the air. That moisture has to go somewhere, but it gets backed up if the condensate drain line is clogged. If the drain line is clogged with too much gunk, your AC unit may not turn on at all.

Regular cleaning can prevent this from becoming an issue in the first place. The process can be messy and a hassle, so call a professional to get rid of all the gunk that's backed up. They have the tools to clean and maintain your condensate drain line properly, so you don't have to get your hands dirty.

9. Dirty or Frozen Evaporator Coil

Ice can form in the evaporator coils, pipes, or even outside the unit. When the air filter hasn't been changed, this is what happens. A filthy air filter necessitates that the central air system work twice as hard to pass clean through a clogged filter. The air that has been circulated for so long around the central heating system forms a reservoir of extremely chilly air inside before it reaches the ductwork, freezing the AC internal components.

10. Dirty Condenser

Condenser coils are responsible for cooling your home correctly. The condenser unit is exposed to dirt and debris that can build up over time in an outdoor unit. If nothing is done to remove it, the effectiveness of the entire air conditioning unit decreases.

If your condenser coils are dirty, call a professional HVAC technician to clean them out. You can schedule regular tune-ups to ensure your unit runs at optimal performance. Keep an eye out for strange noises in the meantime, and clear any debris or landscaping from the nearby area to reduce the risk of damage. A professional will be able to dispose of any gunk and restore your unit correctly.

11. Dirty Drain Pan

Like the drain line, the drain pan helps funnel all the gunk from the air conditioning unit. The drain pan is meant to keep the drain pipe from clogging. When there is standing water in the drain pan, you need to examine the unit for signs of dust and dirt. These particles can mingle with the water and cause a clog.

A professional HVAC technician can clear these out for you so that your AC unit drains condensation properly. If you think the reason for your air conditioning not turning on is due to the drain pain, don't hesitate to contact a professional for assistance.

12. System Not Sized Properly

If you discover your AC not turning on, it may be due to the size of the unit. An improperly sized unit is more likely to break down sooner than later. A smaller unit will work overtime to cool your home, while a larger unit will take up too much power and struggle to stay on.

When there is an improperly sized unit in your home, the only solution is to replace it. This can be costly but will save you money in the long term. Instead of paying extra for a small unit that burns itself out or paying for multiple short-term fixes on a unit that drains your power, you can introduce a new AC unit to your home that will last.

Consult an HVAC professional to determine what size air conditioning unit is best for your home and ensure you don't have a problem with central air not turning on.

13. AC Motor Issue

While the fan motor may fail, other more minor issues with other motors could impact the unit. Various motors could cause the air conditioner to break down if they malfunction. The compressor is the main motor for your HVAC system that keeps everything running and allows the unit to provide your home with cool air on warm days.

If you notice poor airflow or strange clinking or humming noises coming from the outside unit, don't hesitate to call a professional. A loose motor can cause the cabinet to vibrate or shake, causing damage to the inside of the unit. You can also tell if a compressor is going bad by checking for high humidity levels.

If you suspect the compressor motor is dying, consult an HVAC technician for the next steps. Don't let your home get too heated before contacting a professional team to help you.

Also Check Out: Why Is My Air Conditioner Fan Not Spinning?

14. Wiring Issue

Cords and wires are prone to corrosion and fraying. Being outdoors, these wires are exposed to the elements and can be broken over time. While wires can be replaced, you may not notice that they need to be replaced immediately. If left alone, the exposed wires can damage the unit as they fail to deliver electricity properly.

Faulty wiring and loose connections can also be the reason why you uncover your air conditioning not turning on. Additionally, these wiring issues can lead to several other problems with an AC unit. Broken wires can cause electrical problems including tripped breakers and fire hazards.

Contact a professional to do the repairs for you to keep you and your home safe. Leaving exposed wires alone can have devastating results over time, so it's best to take care of the situation immediately.

Trust ARS/Rescue Rooter to Keep Your AC Running

There are more than a few reasons why you might discover your central air not turning on. What's most important is knowing who to call when air conditioning issues arise. Don't hesitate to reach out to the professionals for assistance. The HVAC technicians at ARS/Rescue Rooter are prepared to handle any situation you come across with your air conditioning unit.

Call us now at 866-399-2885 or find your nearest ARS/Rescue Rooter location to schedule an air conditioning repair today!

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Common Questions

How do I reset my air conditioner?

If your inside AC unit is not turning on, you may need to reset it following these steps:

Turn off the power: Find the electrical disconnect box near your outdoor condenser unit. This should have a lever, switch, or circuit breaker. Turn this off to cut the power to your air conditioner.
Wait: You should leave your AC unit without power for at least five minutes to ensure the capacitors are fully discharged.
Restore power: Once you’re done waiting, turn the power back on at the electrical disconnect box.
Adjust thermostat: Set the temperature on your thermostat to your desired level, making sure it is in cooling mode and not at heating or fan-only mode.
Wait for startup: You’ll need to give your AC system time to start up once again. It may take a few minutes before you start to notice it working.

Why would my air conditioner stop working?

If you’re wondering, “Why won’t my HVAC turn on?” there may be a number of reasons. These include:

Power issues: A tripped circuit breaker or blown fuse in your home’s electrical system will prevent your AC from starting.
Thermostat problems: Make sure you have your thermostat set to “cool” and the temperature is set below the current temperature in the room. You may need to replace the batteries in your thermostat if it doesn’t appear to be working.
Clogged air filters: If your air filters are dirty or clogged with debris, the air flow can be restricted. This results in your AC unit shutting down to prevent damage.
Faulty components: Compressors and capacitors can fail over time, meaning you’ll need a professional to repair or replace the damaged parts.
Refrigerant issues: Leaks can lead to low refrigerant levels, another common cause of air conditioning problems.
Blocked condensate drain: Clogs in the drain can cause the AC unit to shut down for safety purposes.

How do I force my home air conditioner to turn on?

If you try to force your malfunctioning air conditioner to turn on, it can make any underlying issues much worse. It’s a better idea to follow the reset the procedure, as detailed above, and make sure your thermostat is set to “cool.” If your unit still won’t turn on, you need to call a qualified HVAC technician to diagnose and resolve the problem before it gets worse.