Air Conditioner Won’t Turn On. Here Are 6 Common Reasons

When you’re sweltering inside your home, nothing is worse than an air conditioner that won’t turn on. As frustrating as it is, there are six common reasons why this may be happening.

In this article, we’ll discuss what they are and what you can do.

1. You Have a Problem With Your Thermostat

If the thermostat hasn’t been configured correctly, doesn’t have enough battery power, or has become disconnected from its wiring, it can prevent your AC from running properly. 

If you suspect that the problem is with your thermostat, you can try changing its batteries, checking the airflow and power supply, and making sure that it’s turned on and set to the correct mode.

    2.  Clogged Air Filters

This is one of the simpler issues to fix but it can become a major problem if leave it unattended. Clogged air filters can reduce the efficiency of your air conditioner and cause it to malfunction. When this happens, it can lead to inadequate cooling, higher energy bills, and more. Clogged air filters should be checked every one to two months and replaced if needed. 

Additionally, air conditioners that are located in dusty areas should be checked more often.

To address a dirty air filter, remove the filter so you can clean it. Once dry, replace the filter and see if you’re air conditioner is working as it should.

    3.  Tripped Circuit Breaker

If your air conditioner won’t turn on, it could be due to a tripped circuit breaker. It's important to check your circuit breaker to see if there has been an overload in electricity or a short in the wiring. 

When there’s a tripped circuit breaker, you’ll usually notice that an entire area of your house loses power, including electric sockets and USB outlets.

If the circuit breaker has flipped, you'll need to reset it and make sure that any damaged wires are replaced.

   4.  Faulty Motors

A faulty motor is another possible culprit when an air conditioner won’t turn on. If a faulty motor is behind your issue, you might have noticed that: 

• The fan inside your air conditioner won’t start.
• The exterior fan blades aren’t moving.
• The blades of the fan are rotating too slowly.
• The air from your air conditioner doesn’t get cold.
• You hear weird noises like rattling, buzzing, and humming.
• Your unit doesn’t always work.

If you suspect that your motor is the problem, you need to call an HVAC service to see if it can be repaired or if the entire unit needs replacing.

   5.  The Outdoor Switch Is Off

Another possible reason why your air conditioner won’t turn on is the outdoor switch has been left in the off position. This is a separate switch for your air conditioner. If you recently had a technician work on your unit, they might have forgotten to turn it back on.

To check if this is the issue, go outside where your AC has been installed. The switch is usually next to the unit. Check that the switch is in the on position and that everything is properly plugged in.

While you’re there, try resetting your air conditioner by pressing the reset button. If you can’t find the reset button, you can reset it from the inside by turning off your thermostat or breaker and waiting a minute before trying to turn your unit back on. Once it’s been reset, check if you’re able to turn your air conditioner on.

   6.  The Coils Are Dirty