Central AC Compressor Not Turning On: 4 Easy Troubleshooting

Got a case of the central AC compressor not turning on? This guide will show you how to troubleshoot this problem.

Central AC Compressor Not Turning On
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How to Troubleshoot Central AC Compressor Not Turning On

Let’s look at how you can troubleshoot your AC unit. Remember, if you’re not comfortable doing this yourself, it’s always best to call a professional.

Checking Electrical Connections

First things first, let’s check those electrical connections. Make sure everything’s plugged in and the circuit breaker hasn’t tripped.

Inspect the Circuit Breaker

Take a look at your circuit breaker. If it’s tripped, you’ll need to reset it. It’s as simple as flipping a switch.

Examine Wiring for Damage

Next, check the wiring. Make sure there are no loose or frayed wires. If there are, you’ll need to call a professional.

Testing the Capacitor

Now, let’s take a look at the capacitor. Remember, this is what gives your compressor the jolt of energy it needs to start.

Safely Discharging the Capacitor

Before you can test the capacitor, you’ll need to discharge it. This involves removing the wires and using a resistor to drain the stored energy. It’s a bit like letting the air out of a balloon – but remember, safety first!

Using a Multimeter to Test the Capacitor

Once the capacitor is safely discharged, you can test it using a multimeter. This will tell you if it’s storing the right amount of energy. If it’s not, you’ll need to replace it.

Evaluating the Thermostat

Now let’s turn our attention to the thermostat. It’s the boss of your AC unit, telling it when to start and stop.

Checking Thermostat Settings

Make sure your thermostat is set to cool and the temperature is set lower than the current room temperature. It’s like telling your AC unit where the finish line is – if it doesn’t know, it can’t start the race.

Inspecting Thermostat Wiring

If the settings are correct, take a look at the wiring. Just like with the AC unit, loose or frayed wires can prevent the start signal from reaching the compressor.

Assessing the Compressor

Finally, let’s take a look at the compressor itself. If everything else checks out, the problem might be here.

Listening for Strange Noises

When you try to start your AC unit, listen for any strange noises. If you hear a humming or clicking sound, it might be a sign that your compressor is struggling to start.

Checking for Visible Damage

Also, take a look at the compressor for any visible damage. If it looks beat up or worn out, it might be time for a replacement.


When to Call a Professional HVAC Technician

If you’ve tried everything and your compressor still won’t start, it might be time to call in the pros. Some things are just better left to the experts.

Situations that Warrant Professional Help

Not all AC problems can or should be solved on your own. Here are some situations where it’s best to call a professional.

Complex Electrical Issues

If you’ve got a complex electrical issue on your hands, it’s best to let a professional handle it. Messing with wiring can be dangerous if you don’t know what you’re doing.

Capacitor Replacement

Replacing a capacitor is not a DIY job. It involves handling high-voltage electricity, and that’s something you don’t want to mess with unless you’re trained for it.

Thermostat Replacement

If your thermostat needs to be replaced, it’s best to let a professional do it. They can ensure it’s properly installed and set up, so your AC unit can run efficiently.

Compressor Repair or Replacement

If your compressor is the problem, you’ll definitely need a professional. Repairing or replacing a compressor is a complex job that requires special tools and expertise.


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Common Reasons Why Your Central AC Compressor Might Not Be Turning On

So why might your compressor be giving you the cold shoulder? There could be a few reasons, ranging from electrical problems to a straight-up broken compressor.

Electrical Issues

Like any electrical appliance, your AC unit relies on a steady supply of power. If there’s a hiccup in the power supply, your compressor might not start.

Circuit Breaker or Fuse Problems

Did your AC unit suddenly stop working? It might be because the circuit breaker tripped or a fuse blew. These safety devices cut off power when there’s too much current. It’s like a bouncer at a club, keeping out unwanted guests.

Wiring Issues

Loose or frayed wires can also cause your compressor to stop working. It’s like trying to sip a milkshake through a straw with a hole in it – you’re not going to get much milkshake.

Faulty Capacitor

The capacitor is like a small battery that stores energy to help kick-start the compressor. If it’s faulty, your compressor might not start.

Identifying a Bad Capacitor

If your capacitor’s gone bad, you might hear a clicking sound when your AC unit tries to start. It’s like trying to start a car with a dead battery – it’ll try, but it just can’t get going.

How a Bad Capacitor Affects the Compressor

Without a working capacitor, your compressor can’t get the jolt of energy it needs to start up. It’s like trying to start a race without a starter’s pistol.

Thermostat Malfunctions

Ever tried to start a car without turning the key? That’s what it’s like when your thermostat’s not working. It tells your AC unit when to start and stop.

Incorrect Thermostat Settings

If your thermostat settings are off, your AC unit might not get the message to start. It’s like sending a letter to the wrong address – it won’t get to where it needs to go.

Thermostat Wiring Problems

Loose or frayed wires in your thermostat can also cause problems. If the wires aren’t securely connected, the message to start might not reach your AC unit.

Broken Compressor

Sometimes, the problem is with the compressor itself. Like any piece of machinery, it can break down over time.

Signs of a Broken Compressor

How can you tell if your compressor’s broken? You might hear strange noises, or your AC unit might not cool your home as effectively as it used to.

Causes of Compressor Failure

Compressor failure can be caused by several factors, such as lack of maintenance, old age, or using the wrong type of refrigerant. It’s like driving a car with no oil – eventually, something’s going to break.

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