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How to Reset an Air Conditioner

Air conditioners are a blessing on a hot Arizona summer day. Hopefully, you have had routine AC maintenance performed so that you are ready for the season. The last thing you need is for your cooling system to go out when you need it most. However, if you have an issue, you can always try a bit of AC troubleshooting to get it back to work, keeping you cool.

A reset may be in order if your AC is not blowing cold air, AC is off but the fan keeps blowing, or has stopped working altogether. This simple process may be all it needs to return to correct operation. You will need a flashlight and a timer for this process. If you have a smartphone, you’ll find it might be a substitute for both. No other tools or expertise is needed to perform a reset.

Why Your AC Needs Resetting

It may be as simple as a power outage. If you have had to cut the power for some purpose or the weather has interrupted your power supply, in some types of air conditioners, the circuit breaker for the AC might have been tripped. This happens when fluctuations in the power flow threaten the system’s operations. The breaker will trip to protect your AC unit from harm. It is a safety mechanism meant to protect your system and home from damage in the event of a power surge but can sometimes kick in if underpowered.

Another reason you might need a system reset might be that you’ve had an electronic issue with your thermostat. If you have set the thermostat to cool, it may not be transmitting this information properly to the rest of the system causing the so-known AC light blinking issue. This is especially true with digital thermostats that function as mini-computers. Just as you would sometimes call a computer repair service and be told to turn your device back off and back on, the same applies to your AC unit.

In either instance, this kind of simple reset can correct the issue and save you a lot of time trying to figure out what the cause of the problem might be when your system just needs to be reset. Follow the directions in the next section to see if a reset might be the solution to your problem.

How to Reset an AC

If you have a window air conditioner, resetting it is relatively simple. Most ACs have a reset button located either near the power plug or within the control panel on the unit. Simply press this button for a few seconds to reset the unit. Once you have let go of the button, wait ten minutes for it to reset, and then turn it back on. If you cannot locate a reset button, simply unplug the unit, wait five minutes, and then turn it back on.

In the event that the problem is not caused by some failure within the system but is merely a bit of confusion in the electronic components that send signals to the system, this should correct your problem. If this fails to do so, you will need to do a bit more investigation into the problem to determine the issue or contact an HVAC technician to take a look at the unit for you. The qualified professionals at AHWA can quickly diagnose the problem and recommend a solution for you.

For central AC units, the process of resetting the system is a bit more complex. Unlike a window AC, the reset button for your central unit will be located on the AC unit outside, but there are a few more steps you’ll need to follow to reset the entire system properly. Just follow the instructions below to get your system back up and running in no time at all.

Steps to Reset your AC Unit

First, turn the AC unit’s thermostat to the “off” position. Once you have done this, you will find the reset button on the ac unit outside. Walk out to where the outside portion of your central unit is located and check the wall of your house near the condenser unit. There, you should find a power supply box with an “on/off” switch. Flip this switch to the “off” position.

Next, return to your house and go to your circuit breaker box with your flashlight and timer in hand. Hopefully, you already know where the breaker box is located. If not, check the basement, utility closets or rooms, and the crawl space. In some cases, you might find it in other locations of your home, especially if it’s older. However, typically you will locate it in one of the locations listed.

Depending on where your circuit breaker box is located, you may need your flashlight to see better, so have it on hand. Once you have found the box, find the breaker that controls the power to your AC unit. These are usually marked either on the breaker or on a chart inside the breaker box door. Flip the breaker to the “off” position and set your timer for 60 seconds.

Once the timer has clicked off 60 seconds, reverse your steps. Switch the circuit breaker that controls the central unit back on and go outside to turn the power back on to your condenser. Next, return to your thermostat and set it back to cool at your desired temperature.

Your AC should start up and begin cooling your home. If it does not, you will need to contact an HVAC technician to take a look at your system and determine the problem.


If the steps above did correct your system, but you find yourself having to repeatedly access the reset button on the ac unit outside, you may still have a more significant problem that needs to be addressed. Though resetting your AC is a simple fix, it is not something you should have to do very often. If you need help, AHWA is just a phone call away. Our highly trained professionals can diagnose the problem with your AC unit and get you back up and running in no time.

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