Air Conditioner Won’t Turn On: Check This Before Calling a Pro

Air Conditioner Won't Turn On

It's a hot day and your air conditioner won't turn on! Before calling a repair service, there's a few things you should check. You may be able to save yourself some money and fix the problem yourself! "Use our quick navigation below to find the problem with your air conditioner"

Although, it's possible that the issue is serious and will require professional repair. There's a good chance that it's one of five common problems. However, keep in mind, if you're able to fix the issue, but the problem happens again, you should always contact a professional. The root cause of the problem could be something serious such as overheating or short circuiting.

What to Do When Your AC Won't Turn On

Power Issues

The first thing to check when your AC unit won't turn on is if there was a blown fuse or a tripped breaker. An air conditioner can blow a fuse or trip a breaker if your home experiences a power surge. Here's how to check:

First, set the thermostat to COOL, and then set the thermostat's temperature setting at least 5 degrees BELOW the current inside temperature. Now, check the following:

Electrical Panel - Check your main electrical panel to see if there's a circuit breaker "tripped" (older homes use a fuse box). If the circuit breaker has tripped, simply turn it off and then back on.

Disconnect Box - Near the AC unit there is sometimes a shutoff box. Within this box there are typically fuses, if one of these fuses has "blown" the unit will not work.

This video will take you thru the process:

Caution: If your air conditioner keeps tripping the circuit breaker or blowing fuses you may have a more serious problem and you should contact a professional for repairs.

Reset Air Conditioner

There are two methods to reset an air conditioner. If you're lucky enough to have a unit with a "reset" switch (located near the outside unit) all you need to do is simply press the switch.

If you do not have a reset switch, you can turn OFF your air conditioner at the thermostat and wait for 5 minutes before turning it back ON.

If resetting your air conditioner solves the problem, you're good to go. But if you find that your AC works for awhile and then you have the same issue again, you need to contact a professional. You most likely have a more serious issue that needs to be addressed.

Shut-off Switch

Many outdoor AC units have a shut-off switch. These switches are typically located near the unit and are within a metal box mounted to the exterior of your home. They are sometimes labeled as emergency shut-offs.

If you recently had work done on your air conditioner, it's possible the workman forgot to flip the switch back to the ON position. 

Inside Power Switch

The reason your AC isn't turning on may actually have nothing to do with the outside unit. The problem could be that the power to your furnace and indoor blower has been turned off. Typically there's a switch located near your furnace. It could be in plain sight or tucked away in a crawl space, closet, or attic. 

It can easily be mistaken as a light switch since it's the same type of switch and it's not uncommon for someone to accidentally turn it off. 

When the switch is in the OFF position, the blower is turned off causing your inside unit to freeze and ultimately shutting down your entire AC system. We highly recommend labeling this switch to help prevent accidentally turning it off. 

Condensate Drain Line

The reason your air conditioner won't turn on could be because the condensate drain line is clogged. When AC units run, they create condensation, which is drained away from the unit thru a drain line.

When the drain line becomes clogged, a safety switch trips and shuts down your air conditioner. If this is your problem, you may be able to unclog the drain line with a shop vacuum, since sometimes the blockage can be removed from the drain line thru suction. 

If your system uses a condensate drain pump to remove the water from your home, it's possible that the pump is not working. When the pump stops working the safety switch will trip, shutting the unit down.