Why Won’t My Air Conditioner Turn On? [AC Repair Troubleshooting]

The reason for an air conditioner not turning on ranges from electrical or mechanical problems inside the system to something as simple as an incorrect thermostat setting. While some issues require a professional, it’s also possible to fix minor issues quickly and on your own.

This article will look at the four most common reasons for an air conditioner not turning on. You’ll learn how to inspect your central air for each issue. And, you’ll discover which ones you can fix yourself — and how to do it, of course.

Before we get any further, we have to stress that you shouldn’t take on any work you’re uncomfortable with. The last thing you’d want to do is damage your equipment — or, much worse, injure yourself — by tinkering with the wiring or internal components.

Instead, call your trusted HVAC contractor if you run up against a problem outside your comfort zone. Here on the Main Line, that trusted contractor is John Cipollone, Inc.

We’ve served homes and businesses from Havertown to Radnor since 1953. You can call us today at (610) 446-7877.

Four Common Reasons Your AC Won’t Turn On (And How To Fix Them)

The four most common problems to check for when your AC won’t turn on are:

• Thermostat Problems
• Clogged Air Filter
• Electrical Issues
• Mechanical Problems

Read More: Pre-Season Maintenance Call Gets Ahead Of HVAC Problems [Case Study]

Thermostat Problems

The first place to check is the thermostat. The cause could be an incorrect setting or low battery, causing it to send the wrong signals.

How To Fix It

Check to make sure you’re on “Cool.” It’s pretty easy to forget to switch over from “Heat” before setting the temperature for the warm weather. Or, if the fan runs but the AC won’t turn on, you may be on “Fan Only.”

That setting circulates air through the house without warming or cooling it.

Set the call temperature to 78 degrees (that’s the optimal temperature for comfort and energy efficiency), and ensure there’s no Low Battery warning.

Read More: What To Check When Your AC Is Running But Not Cooling

Clogged Air Filter

If the thermostat is okay, it’s time to head down to your furnace and check the air filter. Your central air uses the blower motor and other parts from your heater. So, an issue with the filter affects your cooling.

The most common problem is a filter that’s been in the furnace too long. If one gets enough dirt and dust built up on it, air can’t pass through it to reach the AC coil inside the system.

When that happens, the air conditioner recognizes there’s no air coming in and will either shut right off or not turn on at all.

How To Fix It

Replace your old filter with a new, clean one. You’ll notice the cloth screen on the new one is white. If the one you pull out is gray or dark gray, it’s clogged and probably caused the problem.

If the system turns on after that, you’re all set. Then, change the filter every four weeks when the heat or AC runs. And, every 12 weeks when it’s not.

Read More: Why Does My Air Conditioner Keep Turning On And Off?

Electrical Issues

You can’t fix most power supply problems on your own. But, you can at least get an idea of what’s wrong. Common issues are a tripped circuit breaker, blown or damaged fuse, or disconnected or damaged wires.

We’ll tell you how to check for a few of these visually. But it’s vital that you don’t try to repair, or even touch, any damaged or disconnected wires. You risk damaging the system or, much worse, hurting yourself.

How To Fix It

Check your electrical panel for a tripped circuit breaker. A power surge may have caused it to shut off. Flip it back on, and if it stays that way after the AC turns on, you’re set. If it keeps tripping, keep it off and call a professional because there’s another problem somewhere.

Next, head outside and check the condenser for any disconnected, damaged, or broken wires. It’s not uncommon for animals to nest or chew through wires around the unit.

Last, check the wires going into your furnace. Carefully remove the panel and see if you notice any loose, disconnected, or damaged wires. Turn off the system from a shutoff switch or the breaker if you see any. Then, call your HVAC contractor.

Read More: PECO Rebates For High-Efficiency Air Conditioners And Heaters

Mechanical Problems

Once again, you can’t fix a mechanical problem yourself. The job calls for a professional AC repair tech. But, we can still tell you what to watch for.

Blower Motor

The blower motor in the furnace draws air in from the house and then back out through the ductwork. If that piece is damaged or broken, the system may not start. Or, you hear it turn on but don’t get any airflow.

Listen for strange noises from the furnace when the system attempts to start. Check for burning smells from the unit or coming through the vents.

Belts And Bearings

The AC uses belts that can crack, wear out, or slip off over time. When that happens, the system may not turn on. Or, it will start but won’t keep running.

In this case, listen for slapping sounds from the belt flying around off its track. Or squealing noises if it’s dried out or cracking.

Once again, you’ll need a professional to repair it.

Air Conditioner Repair In Radnor, PA And On The Main Line

John Cipollone, Inc. has provided air conditioner repairs for Radnor, PA and other Main Line homes and businesses since 1953. Today, we have an excellent reputation with an A+ BBB rating and hundreds of five-star Google reviews. Click below or call us at (610) 446-7877 to set your appointment.