9 Common Reasons Your AC Won't Turn On

While most AC systems will last anywhere between 15 and 25 years, your system’s lifespan will vary based on how well you take care of it. You need to be sure to maintain your AC and keep it in great shape.

If you fail to maintain your HVAC system, you may find that sooner or later you have a hard time turning it on at all. In these cases, it’s important to know what to look for so that you can get to the bottom of the problem.

Fortunately, we’re here to help. Here are the most common reasons why your AC won’t turn on.


1. Thermostat Problems

One of the top possible reasons why your AC won’t turn on is because there are problems with your thermostat.

When your thermostat starts malfunctioning, it can have a big impact on the performance of your AC unit. It may have a difficult time communicating with your air conditioning system and switching it on.

To diagnose your thermostat problems, the first thing that you should do is to check your thermostat’s screen. If the display is blank, then you should try to switch it on.

If the thermostat doesn’t turn on, then you may need to replace the batteries. There’s a chance that this may be all that you need to do to get your thermostat and your AC system working again. However, in some cases, this won’t be enough to fix the problem.

Other things that could lead to thermostat issues include problems with the components, blown fuses, or the collection of debris. There could also be a loose wire or screw in the thermostat as well. You’ll need to check for these problems or hire a professional to see if you can get it to turn on again.


2. Incorrect Temperature Readings

One possible reason that your AC system is turning off is that your thermostat is getting incorrect temperature readings.

Depending on where your thermostat is located, it may have a hard time detecting the true temperature of your home and could be switching off as a result. If your thermostat is in an area of your home where temperatures can change easily or where it’s not the same as the rest of your home, there could be problems. For example, a laundry room may not have the same temperatures as the rest of your home.

To deal with incorrect temperature readings, you might simply need to move the thermostat to a different area of your house.


3. Leaking Refrigerant

If your AC system has low refrigerant due to a leak, it could also prevent your AC system from turning on properly.

Refrigerant is located in your system’s AC coils and could leak if the AC coil is cracked. Refrigerant is important for an AC and is what helps to provide the system with cool air. If the AC coil has experienced damage and your refrigerant has leaked out, then your AC may have a hard time switching on.

If you think that this could be your problem, you’ll need to hire a professional to check refrigerant levels. They’ll help ensure that the correct amount is filled and can help fix the problem with your AC coil.

Keep in mind that there are several early signs that you could have a refrigerant leak. If you’ve been noticing that your AC was having a hard time cooling your home before it stopped turning on, it could be a sign that you have a refrigerant leak. You might also notice hissing noises or high electricity bills before your AC stops turning on as well.


4. Condenser Problems

The outside AC unit that’s part of your HVAC system is known as a condenser. Sometimes the problems with your AC system lie in problems with the condenser.

If you haven’t been maintaining the condenser properly, it could get dirty and it may become hard for it to do its job. It may end up tripping your circuit breaker or preventing your AC from turning on.

In the case of a window AC unit, there might simply be something wrong with the cord. You’ll want to ensure that the cord is plugged in and that it’s not broken or damaged in some way.

To clean your condenser unit, you’ll typically want to hire a professional for the job. Cleaning it improperly can cause damage and can make the problem worse.


5. Capacitor Damage

Especially if your AC system is a bit older, your capacitor may be causing your issues. A capacitor that isn’t working correctly can lead to AC issues and a failure of your AC system to turn on. The capacitor is an important part of your AC system and is connected to your motor, helping it to get started and keep running.

Overheating could lead to the capacitor having problems. This overheating could affect your outside unit on hot days, for example. Your equipment may also experience damage for other reasons such as power outages or it could be losing its strength simply due to being old.

It’s important to get a professional to replace your capacitor if it’s causing problems since there could be a risk of shock when doing so.


6. Blown Fuses

Another thing that may prevent your air conditioning from turning on is a blown fuse. You should be sure to check your fuse box and ensure that all fuses are working correctly. Make sure that you turn off the power before doing this in order to prevent the chance of electric shock.

To test the fuses, you can use a tool known as a multimeter. This will allow you to do a continuity test and find out whether all of the fuses are working correctly or not. If any of the fuses aren’t working as they should, you can buy a replacement fuse at a hardware store.


7. Dirty Air Filter

A clogged air filter is also an issue that can lead to problems with your AC system.

It’s important to replace your air filter regularly. If you forget to do so, it can accumulate a lot of dust and debris.

This dust and debris can significantly alter airflow and can cause problems. Blocked airflow can lead to the coils freezing and can prevent your AC from doing its job.

In some cases, the ice can grow on the coils and make it impossible for you to turn on your AC unit at all. Replacing the air filter can help you to solve this problem and will allow your HVAC system to start working properly again.


8. Clogged Drain Line or Drain Pan

Another thing that can prevent your AC from turning on is a clogged AC drain line or drain pan.

The drain pan is beneath an indoor unit’s evaporator coils. Water collects here and goes into the drain line outside. If the drain line and drain pan aren’t cleaned regularly then they could become clogged and can have issues.

If they are full, it can trigger the float switch and your AC could be switched off. It does this so that the water won’t leak from the clogged drain pan and can cause water damage to your home.

You’ll need to be sure to clean the drain pan out so that you can turn your AC on again. You may want to use a wet/dry vacuum to clean up the blockage or get an AC repair service to provide air duct cleaning.


9. Tripping Circuit Breaker

If your circuit breaker has tripped, your AC may not come on like it’s supposed to.

There are many reasons why your circuit breaker may have been tripped. It could be because of a power surge after a storm or because you were using too many appliances at once.

You may want to check your electrical panel to ensure that your AC switch hasn’t been set to the off position at some point. If the AC switch is off, you may simply need to switch it back on in order to get your AC working again.

If you’re having a repeated problem with the circuit breaker switching off, then you might need to find out what the cause is. You’ll need to diagnose the problem and may need to hire an electrician to get to the bottom of the issue.


Checking for the Common Reasons Your AC Won’t Turn On

If your AC won’t turn on, you need to get to the bottom of the issue. There are many things that can lead to AC problems including thermostat issues, blown fuses, condenser failure, and much more.

If you want to get your AC problems dealt with, you should consider hiring a professional. Get in touch today to learn more about what Kaiser Air Conditioning can do for you and to schedule a free consultation.