When you're in the middle of a heatwave, the last thing you want is to deal with is a broken air conditioner. Unfortunately, that can happen more often than you think, especially when it's running around the clock. If your air conditioner shuts off, and won't come back on, use the information provided here to locate the problem.
Your Disconnect Switches Are Off
If your air conditioner has stopped working, the first thing you should do is check the thermostat. You may just need to change the batteries. However, if a battery change doesn't solve the problem, there may be an issue with your disconnect switch. Your central air conditioner unit has two disconnect switches—one located inside the house and one located outside on the main AC unit. If either of the disconnect switches has been turned off, your air conditioner won't work. If either of those switches is in the "off" position, switch them back to "on" and test your AC again.
You've Lost Power to the Circuit Breaker
If you've checked the disconnect switch, and your air conditioner still won't turn on, the circuit breaker may have been tripped. This can happen during peak operating times when transformers are overloaded. It can also happen if your own energy use is high during a heatwave. Check your circuit breaker to see if any of them have been tripped—or moved to the "off" position. If you do find one, switch it back to the "on" position. In most cases, this should reactivate your air conditioner.
Your AC Has Blown a Fuse
If you haven't had luck with the disconnect switches, or the circuit breakers, take a close look at the fuses. Your air conditioner operates through a system of fuses and circuits. If a fuse burns out, your air conditioner won't work. Luckily, fuses are easy to replace. Locate the fuse for the air conditioner. If it appears to be burned, you'll need to replace it and try your air conditioner again.
Your Capacitors Are Shot
If you've been unable to locate the reason why your air conditioner won't work, the capacitors may be shot. Like the disconnect switches, your air conditioner has two capacitors. One of the capacitors is responsible for turning the air conditioner on, and the other one is responsible for running the system. If either of the capacitors fails, your air conditioner won't operate at all. If your capacitors have failed, you'll need to contact air conditioner repair services.