Air Conditioner Not Turning On [Problems Solved]

This article explains steps to take if you find your air conditioner not turning on or if you have trouble powering other parts of the unit.

air conditioner not turning on

Air Conditioner Not Turning On – How to Fix

Check the following if your air conditioner does not turn on:

1. Power Switch

The air conditioner typically has a power switch near where you mount it, but the type of switch depends on the system. Some have no visible switch near the indoor unit except the wall outlet for the power cord. Others have a dedicated switch near the outdoor unit that turns it on or off. But all air conditioners have a power switch that controls its functions on the body or remote control.

Check to see if the switch on the wall near the unit is off. It seems like the most unlikely reason, but someone may accidentally turn it off. Also, check the switch on the remote to turn on the air conditioner, especially if you cannot locate the wall switch. In addition, the switch for the condenser outside the house must be on to power the outdoor unit. Otherwise, the air conditioner will fail to work.

2. Thermostat

An air conditioner thermostat acts as its control panel and allows you to govern the system’s functions. You can turn the unit on or off from the thermostat and determine the mode. The remote control can also handle these functions, but it is not always available or convenient. So, if the air conditioner does not turn on, one of the first places to check is the thermostat.

Look at the thermostat; its screen should be lit if you are sure it is on and working. If the screen is not lit, it may indicate a power problem. And that also explains why the air conditioner is not turning on, especially since it is connected to power. If the thermostat works with electricity, check its connection and make the necessary adjustments. Otherwise, there may be an internal wiring problem. But if it works with batteries, they may be due for a replacement.

However, if the batteries or power connection is in good order but the thermostat does not work, there may be a wiring problem that needs immediate attention. Turn it off, unmount it from the wall, and open it. Check for dirt or corrosion; clean the dirt if there is any and remove signs of corrosion. Ensure there is no damaged fuse; consider replacing it if there are other underlying issues or have a technician fix them.

Turn on the thermostat and adjust the temperature to about five degrees lower than the room temperature. Set the fan speed and give the air conditioner a few minutes to see if it begins working. Place one hand in front of the vents to feel the air; if there is cold air, the problem is solved. But if there is no air from the system, the problem may stem from a faulty internal component.

3. Air Filter

The air filter in an air conditioner seems like a part that you can overlook, and it tends to work for some time. However, the air conditioner may eventually stop working if the filter is neglected for too long. The filter is integral to the system’s functionality, filtering the air that flows in and out of the air conditioner. Over time, it builds dirt and needs to be cleaned or replaced. But many air conditioner users neglect to check it until the unit stops working.

A significantly dirty air filter in an air conditioner restricts airflow, and the system works harder to produce cool air. As a result, different system parts prematurely wear out due to the extra strain without much result. The filter can also lead the outdoor condensing unit to freeze because of the excessively cold refrigerant in the system. If there is not enough warm air reaching the refrigerant as it flows between the evaporator and condenser coils, it will cause the refrigerant line in the condensing unit to freeze. 

And if the condenser is frozen or fails to work, the air conditioner will not turn on at all. Therefore, open the indoor unit to locate the air filter. You can also consult the air conditioner’s user manual for the location of the filter if it is not readily visible in the air handler. Remove and replace it if you have never done so in six months or more. Note that if the air conditioner shuts down or does not turn on due to dirt from the air filter, replacing the filter alone may not fix the problem. You may need professional assistance to check other parts and make necessary changes.

Typically, an air filter should be replaced every three months, although some types last longer because of their design. A smart thermostat will help you determine when the filter is due for a replacement if you use a ducted air conditioning system. That way, you do not put undue strain on the air conditioner’s components and cause the entire system to shut down prematurely.

4. Condensing Unit

The outdoor unit has the responsibility of removing heat from the system. When the refrigerant absorbs the heat from the warm indoor air, it moves to the condenser for heat transfer. This process keeps the air conditioner efficient. However, the condenser’s location outside the house easily gets dirty. As a result, it needs regular maintenance to keep it functioning. 

Otherwise, dirt can impede its heat dissipation capacity and can eventually shut down the system. Moreover, when the condenser is significantly dirty, it tends to work harder to remove heat from the system. Consequently, it draws a lot of power, which trips the breaker and shuts down the system.

If the air conditioner is not turning on because of dirt buildup on the condenser or poor maintenance, cleaning it yourself may not solve the problem. At this point, you will need professional assistance to determine the extent of the problem and provide a permanent solution. Afterward, you can run regular checks and clean the unit as recommended.

5. Capacitor

The capacitor can cause the air conditioner to develop trouble turning on if it fails. An air conditioner works with a compressor and motor, and the capacitor provides the power to get them up and running. There are two types: a start capacitor and a run capacitor. A start capacitor provides the initial power to get the motor started, while a run capacitor supplies the voltage to keep it running. 

It disconnects from the circuit when the compressor or fan motors reach a comfortable running speed. If the capacitor fails, you may hear the compressor clicking and trying to turn to start. The same is true for the fan motors. And if that is the case, you may need to replace the capacitor, but it is not a job to do yourself unless you have the training. 

Capacitors store an electric charge that last hours after disconnection from electric power. So, they need to be discharged before you can safely remove them. Moreover, it can damage the motor to which it is connected if you try removing it without discharging it. Have an HVAC technician replace the component.

Possible Causes of Capacitor Failure

An air conditioner capacitor may stop working due to power fluctuations. Since it holds a significant amount of electric charge, it is vulnerable to spikes or surges. Consider using a surge protector if you live in an area with regular outages or power surges. Another possible cause is overheating. This is especially true for condensing units installed on the roof; capacitors are in the condensing unit. They are exposed to direct sunlight and can burn up on scorching days. Power surges can also cause capacitors to overheat.

Constantly setting the air conditioner to the coldest or warmest temperature causes the system to work harder than usual, affecting the capacitor. You may want to keep the temperature settings at the recommended points even if it is a hot or cold day to prevent premature damage to the system’s components. Lastly, the capacitor’s age can also affect how well it functions. Eventually, it stops working if you use it for a long time.

Other Issues

If you do not use your air conditioner for long months, it may have a hard time turning on when you need it. You may have to leave the air conditioner during cold months or if you travel, but always run a service check before usage. If you find that it does not start when you turn it on, call an HVAC technician to test the parts, clean the necessary components, and get the air conditioner working again.

There is a chance that the closed system is leaking refrigerant. And if the air conditioner has low refrigerant, it cannot function. Refrigerant runs in a closed loop and should never have to be refilled unless there is a leak. Such a leak needs immediate attention because of the health impact and the damage it can cause to the air conditioner. Hire a technician to check for possible leaks and fix them.

Another possibility is that the air conditioner has reached the end of its life. If you have used it for up to 13 years, it may be time to start looking for a new cooling system. Most air conditioners have a life span of 15 to 20 years, and they begin to malfunction when they cross the 13-year milestone. This time frame depends on the usage and maintenance level. If you regularly maintain the air conditioner, it may last longer. But if you have an issue turning it on and the system is old, replace it.

Note: Follow the steps above to fix an air conditioner furnace that will not turn on if you have that problem.

Air Conditioner Not Turning On After Cleaning

Check the switch to ensure it is still on after cleaning the air conditioner. You may have turned off the indoor switch while cleaning, or the power connection may have tripped. Also, ensure nothing is damaged in the course of cleaning the unit. 

You may want to reset the system by turning it off at the thermostat and breaker for a few minutes. That may fix the problem. However, you may not need to reset it; turn on the power switch, ensure the thermostat is on, set it to Cool, and set the fan speed to the desired setting. The air conditioner should work.

Air Conditioner Not Turning On After Winter – Fixed

Several issues cause an air conditioner not to turn on after winter. Typically, you turn off and sometimes store an air conditioner to protect it from the harsh winter temperatures. Other times, you may not store it, but there is no usage, which means the air conditioner lies dormant. As a result, there is a problem with turning it on after winter because of the long phase of non-usage.

First, check the circuit breaker. Each house has a central breaker that controls the house, and you may find individual breakers for heavy-duty appliances. Understand how your house works and find the breaker for the air conditioner. If there is a separate breaker, check to see if it is tripped. 

Reset it and see if the air conditioner works. If not, there may be one or more blown fuses, and you need to replace them. Use the help of a professional to fix this issue if it is beyond your skill set. You can also check the disconnect near the outdoor unit to ensure it is on; it may have tripped, or someone may have turned it off. Also, there may be a switch somewhere near the indoor unit; check to ensure it is not off.

Second, check the air filter. This depends on how often you changed it and the last time you did it before winter. If you have not changed the filter in a while, it is time to inspect and replace it. Leaving the filter for several months may require a complete replacement even if you replaced it before turning it off for winter.

Third, ensure the thermostat is working. The screen should be lit, and you should be able to turn the air conditioner on using the thermostat. If the thermostat is working, set the mode of operation to Cool, adjusting the fan speed. Then, wait to see if the air conditioner works. If so, your problem is solved. Otherwise, there are other issues to check.

Next, check the drain line and pan. If the pan has standing water in it, it indicates the drain line is clogged with dirt. And if there is standing water, it may trigger a float switch to turn off the air conditioner and keep it from turning on even if you try. It is a protection design to prevent damage to the air conditioner. If you have not cleaned the air conditioner in a while, it may be time to check the drain line. Use a wet/dry vacuum to clear the debris and empty the pan. Take the opportunity to clean other parts of the air conditioner.

Consult the user manual to see if the air conditioner has a dedicated reset button. Not every air conditioner brand has this button, so you may have to disconnect the from electric power ot perform a reset. However, if there is a button, check the reset instructions in the manual and follow it to reset the unit. It may fix minor errors and get the system working again. If nothing else works, contact the manufacturer for service or hire an independent technician.

Air Conditioner Not Turning On with Thermostat – Solved

An air conditioner thermostat works like a control panel where you can govern the system’s functions. You can turn on the air conditioner and set the mode of operation on the thermostat. Find the fan and set the speed on the thermostat. In other words, the air conditioner may not function if the thermostat malfunctions.

So, if you find the air conditioner not turning on with the thermostat, it may be because it has faulty wiring or the batteries are dead. It may also mean the power connection is off if the thermostat works with electricity. If it works with batteries, remove them and put new ones in their place. That should get the thermostat working again if the batteries are the problem. 

Ensure you put them in the correct order with the polarity in mind. Check where the + sits in the battery compartment and insert the batteries with the + sign on that side. The same applies to inserting the batteries with the – sign in the correct direction. Otherwise, the thermostat may not work, and the air conditioner may not turn on at all.

However, if the thermostat works with electricity, it may not be correctly connected. There may also be corrosion or age. Hire a technician to check and fix the thermostat if necessary. An alternative is to replace it.

Air Conditioner Not Turning On Outside – What to Do

If the outdoor condensing unit is not turning on, the first thing to check is the switch near it. There is a disconnect next to the condenser that powers it, and if the box is off, the condenser does not work. It typically has an On/Off that you can check and correct if necessary. If you are unsure how to use it, get a technician to ensure the disconnect is working and turn it on if it is off.

But if the disconnect is on, check to see if the circuit breaker has blown a fuse. The outdoor unit may have a separate fuse controlling it, and if this fuse stops working, the unit will not turn on while the indoor unit functions. Loose or aging wires and strain can cause the fuse to blow. When the circuit has too much load on it, the fuse may overheat and stop working. Therefore, check the fuses and replace faulty ones. You may need an electrician or HVAC technician for this job.

The capacitor may have a problem. It is the part that provides power to the motors and compressor, which make up the condenser. So, if the capacitor fails, the condenser may stop working due to a loss of power. Therefore, check the capacitor and replace it if necessary. Follow this guide to test and replace the component.

The thermostat must be set to Cool for the indoor and outdoor units to function. So, ensure the thermostat is on and set to the cooling mode. When you activate it, check to see that the blower is working and the condenser fan is operating. Also, listen to the hum of the compressor. If these are in order, you are good to go. But if the indoor unit is working but the outdoor unit is not, yet the thermostat is functioning, you know another fault is causing the problem with the condenser.

Lastly, the air conditioner may be running low on refrigerant. If that happens, it means the coils are leaking, or the refrigerant pipes are punctured. If you suspect a gas leak, the first step is to turn off the air conditioner. Keep it off while you call for professional assistance. If the leak is not excessive, there may still be a chance to preserve the outdoor unit. Otherwise, prolonged and excessive leaks in the outdoor unit may damage the compressor and stop the air conditioner from working.

Air Conditioner Not Turning On in Car – Quick Fix

The air conditioner in your car may not turn on for several reasons. One is that the cooling fans are not working. The fans move the cooled air from the air conditioner into your vehicle, just like a blower moves the cooled air from your home air conditioner into the room. If the fans stop working, it may be hard for the air conditioner to work. Let your mechanic look at the cooling system, determine if the fans have failed, and fix them.

Another possible reason is that the condenser has a problem. The condenser comprises fins or coils that transfer heat out of the air conditioner and play other vital roles in the cooling process. So, if it becomes clogged with dirt or develops other faults, it stops working, causing the system to stop working. It is crucial for the condenser to be free of debris and efficiently dissipate heat out of the system for the air conditioner to work.

The compressor may not be working as it should. Since it plays a central role in how the refrigerant moves and whether or not other key components function, the air conditioner may not turn on if the compressor malfunctions. And if the compressor is faulty, consider the cost of replacing it or purchasing a new air conditioner; compressors are usually expensive.

Additionally, the system may have a refrigerant leak. Such a leak means there are tiny holes in the refrigerant lines or coils, causing the gas or liquid to escape. Without refrigerant, the air conditioner cannot work. In some cases, it may turn on, but the strain of running without refrigerant will prematurely damage the unit. It is best to leave the unit off until a mechanic can check for a leak and fix it.

You may also want to ask the mechanic to check for damaged fuses, loose electrical connections, defective capacitors, an issue with the control module, and other such problems if nothing else seems to cause the problem. These issues are pretty easy to fix, but they must get immediate attention to avoid an acid buildup. Such a buildup can completely damage the air conditioning system, requiring a replacement.

Air Conditioner Not Turning On After a Power Outage – Solution

If you find that your air conditioner does not turn on after a power outage, reset the unit. Some air conditioner models may have a dedicated reset button for such purposes, so consult the user manual to determine whether or not your unit has a reset button. If it does, locate it and press it according to the manual’s instructions. The air conditioner should reset and resume working after the reset.

However, if your air conditioner model does not have a reset button or you cannot locate it, go to the thermostat and turn the unit off. Turning it off at the thermostat prevents it from requesting cooling while you reset the outdoor and indoor units. Next, go to the circuit breaker and turn the breaker controlling the air conditioner to the Off position. Then, turn the breaker on again.

Do not turn on the thermostat after turning on the breaker; wait about thirty minutes before powering the thermostat. This time allows the indoor unit to reset, which does not happen if the thermostat requests cooling. Therefore, keeping the thermostat off throughout the reset process is crucial. Finally, turn on the thermostat and set the mode of operation to Cool. Adjust the fan speed to the correct setting, and the air conditioner should resume working after a power outage.

Air Conditioner Compressor Not Turning On – Quick Fix

The compressor is the central part of an air conditioning system. It does not only help the cooling but also provides the power for other components to function. So, the air conditioner will not work or cool if it does not turn on. 

Several problems cause the compressor to stop working; check the air filter, power connection, relay and capacitor, and the condenser coil. The last thing to check is the compressor, but only if other components more likely to cause the problem are in good working condition. This article on an air conditioner compressor not turning on contains detailed instructions on troubleshooting and fixing the problem.

RV Air Conditioner Not Turning On – Fixed

The power source is the first thing to check if your RV air conditioner is not turning on. Every RV or camper has a power output capacity. That means it can carry only a specific number of appliances, and the heavier the voltage requirement of the appliances, the fewer the ones the camper can carry. Refrigerators and air conditioners consume a lot of energy, so if you are already using several appliances, it may reduce the available voltage for the air conditioner.

Therefore, check the circuits to determine whether or not there is an overload. The overload may have caused the circuits to fry or reduced the available voltage. You may need an electrician to see if that is the problem. Then, the electrician can reduce the load to make more voltage available for the air conditioner.

Also, ensure the unit is properly connected to electric power and the power switch is not off. If these are in order, examine the air filters to clean or replace them. Regular maintenance helps you check the filter to prevent clogging. If the air conditioner is clogged with dirt, it may eventually stop working. The filter must be cleaned every two weeks and replaced every three months.

In addition, check the thermostat to ensure it is in good working condition and switched on; it must be set to Cool, and the fan speed must be correct. Adjust the settings as needed and check the air conditioner. If necessary, replace the batteries, especially if you have been using them for over a year. If replacing the batteries does not work or the thermostat malfunctions due to corrosion, it may be time to replace it.

Finally, check the compressor and refrigerant level. A qualified HVAC technician is in the best position to test the compressor and determine whether or not there is a refrigerant leak. Contact the manufacturing brand or hire an independent technician for further assistance.

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