Is it just me, or does this always happen when you need it the most?  

You just got home. You’re broiling hot, expecting to walk into a cool house. But no—for some reason your air conditioner isn’t turning on.

The good news is there are a lot of reasons for this to happen, and in many cases the fix is something simple. Something that will have you cool again in a fairly short time.

Of course, some of the reasons will be more serious, meaning you’ll need to call a pro. And if you want to get cool right now, you need to get in your car and turn the AC on in there.

5 Plus Tips on How to Get Your Air Conditioner Running Again

    What to do if Your AC Won’t Turn On
Make Sure Your AC in Turned On
Check Your Thermostat
Change or Clean Dirty Air Filters
Clean Your Condenser
Find Out Why Your Breaker is Tripping

Before we begin, I want to point out that some of these may have you saying, duh, of course that isn’t the problem.

Don’t be too sure. Sometimes it’s the simplest thing we overlook. So do yourself a favor and check those things as well.

1. Make Sure Your Air Conditioner in Turned On

There’s a good chance you haven’t used it with any regularity, but your AC does have an on/off switch, just like any other appliance. It’s just not directly on the unit.

It could have accidently been turned off by someone not realizing what they were doing.

Solution: Find your AC’s power switch. It will be somewhere close to where it’s installed. Flip the switch. If you hear your AC crank up, you’ll know you’ve solved the problem.

2. Check Your Thermostat

While your thermostat doesn’t power your system, it does tell it to turn on and off. But what if it can’t communicate with your air conditioner?

Take a look at the display. Is it fully lit up? Perhaps looking a bit faded?

It may be time to check your batteries. Even if the display is working there is a chance your batteries are low in voltage—enough to impact the performance of your air conditioner.

Solution: Change your batteries. If you have a voltage tester, do that first since there is no need to change them if it’s not necessary.

Next, to further test your thermostat, take it off the wall and look for the following:

  • Blown fuse. If necessary, replace it.
  • Corrosion around the battery terminals. They may need cleaning.
  • Lose screws or wires that need to be tightened or reconnected.

Check out the following video for tips on troubleshooting your thermostat

3. Change or Clean Dirty Air Filters

dirty air filters
Change or clean your filters

Air filters need to be changed or cleaned regularly—usually about every 3 months. When was the last time you changed yours?

If they are covered with thick dust, airflow is restricted. This means your system has to work harder to move air, and this can cause your blower motor to burn out. Or your system could stop working entirely because blocker air has frozen over your evaporator coils.

Solution: Check to see if your filters are ready for a change or clean. And if you have an ice buildup on your evaporator coil, just give it time to melt.

4. Dirty Condenser

keep the condenser clean
Keep the Condenser and the area around it clean

Your condenser is located outside. That big metal box beside your house. The inside evaporator coil collects heat and humidity from your home and pushed is outside to the condenser where it’s released.

Since it’s sitting out there exposed to the elements it will get even dirtier than anything inside. Dirt gets through the grate, along with leaves, twigs, gravel, grass—all kinds of things that will clog up your condenser.

Once this happens the condenser has to work longer and harder, trying to keep up. Eventually, this can pull too much current and trip your circuit breaker.

Solution: Take a trip outside and do walk around your condenser. Get a broom if necessary and clear away any build up of dirt and stuff.

However, that’s not enough. Watch the following video for a walkthrough on what to do.

5. Tripped Circuit Breaker

There are multiple reasons for a tripped breaker. I touched on one above where a dirty condenser could ultimately lead to your AC tripping a breaker.

Here are some things that can lead to a tripped breaker:

  • Dirty condenser
  • Dirty filter
  • A short in the motor
  • Faulty compressor
  • Issues with the breaker itself

I’ve dealt with the dirty condenser and filters above, but what about the other 3? Unfortunately, these aren’t simple fixes.

A Short in the Motor. Your HVAC motors can run for hours on end. And if you aren’t keeping up with service and maintenance, they’ll work harder and longer than they were designed to do. This can ramp up heat and the insulation your wiring can break down, leading to a short in the wiring.

According to Wikipedia, “A short circuit (sometimes abbreviated to short or s/c) is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circuit.”

That “excessive current could result in a fire but before that can happen, your circuit breaker trips, cutting off the current.

Faulty Compressor. As your compressor—the big unit outside which is the main part of your system—starts to age, it can begin to do something called hard starting. When it does this, it’s pulling more than the usual voltage, and this will cause your circuit to trip.

If this is what’s happening, you’ll need a service call. And maybe a new air conditioner.

Finally, the issue may have nothing do you with your air conditioner. You may have an electrical problem that needs to be addressed.

Solution. If your breaker is tripping for any other reason for the last—when the breaker itself is the problem—there is no solution at the breaker. You’ll need to identity the cause for the tripped breaker because it’s only a symptom.

Conclusion

To recap, here are some things to check if your AC isn’t turning on:

  • Make sure your air conditioner in turned on
  • Check your thermostat
  • Change or clean dirty air filters
  • Clean your condenser
  • Find out why your breaker is tripping

Some of them are easy fixes but some might mean a new air conditioner. Hopefully it’s one of the first. Usually, it is!

Thanks for reading. Why not check out our related posts and guides while you’re here?