Why Won’t My AC Compressor Turn On?

Is your air conditioner struggling to keep your home cool? Call JC Heating & Cooling at 708-968-3131.

why won't my ac compressor turn on

As the premier AC repair company in Hodgkins, IL, “Why won’t my AC compressor turn on” is one of the most common customer queries we receive.

If your air conditioner won’t start up, it’s highly likely that there’s an issue with your compressor. This is concerning to hear, but there is no reason to panic.

It’s not the end of your air conditioner. Even in a worst-case scenario where the compressor is dead, your HVAC technician can install a new compressor and bring your air conditioner back to life.

But why do compressors stop working in the first place? We provide the answers in this article.

Why Is the AC Compressor Important?

The compressor is integral to an air conditioner’s function. It’s responsible for circulating the refrigerant through the system. Therefore, there’s no cooling without it.

You’ll find the compressor within your air conditioner’s outdoor unit, next to other components like the coil, fan, and condenser.

What Are the Warning Signs of Compressor Problems?

Like other parts of an air conditioner, your compressor most likely won’t break down without warning. Here are some signs your compressor may stop working soon:

  • Warm air coming through your system while it’s running
  • Circuit breaker constantly trips as the unit runs
  • Noisy operation
  • Shaky outdoor unit when the air conditioner kicks in

Reasons Why Your AC Compressor Won’t Turn On

If you’re asking, “Why won’t my AC compressor turn on?” consider the following potential reasons. 

Power Supply Problems

The first thing you should do when your AC compressor doesn’t turn on is confirm that it’s receiving power.

Check the thermostat to ensure you’ve set it to “cool.” Next, lower the temperature on the thermostat to ensure it’s a few degrees lower than the room temperature to see if the compressor will kick in. If nothing happens, check the system switch to confirm it’s still switched on.

Keep in mind that this step is only necessary if there is no sign of power going to the air conditioner. So, if the fan is running, for example, but the compressor isn’t, the problem lies closer to the compressor unit.

Faulty Wires

Burnt or disconnected wires in your air conditioner’s outdoor unit can keep your compressor from turning on. You can visually inspect the outdoor unit to rule out or confirm this possible cause.

First, you’ll need to turn off the power supply to the outdoor unit. Then carefully remove the metal cage to inspect the wires for inconsistencies.

If you see any issues, it’s important that you don’t attempt repairs on your own. You’ll most likely make things worse, in addition to putting yourself in danger. Call in an experienced technician to handle the repairs instead.

Starter Relay and Capacitor Damage

The compressor relies on power from the capacitor and relay to start and run. The capacitor holds electricity and supplies the initial jolt of electricity the motors need to start running. It also continues to supply power to the compressor and other parts throughout the cooling cycle.

The starter relay is the bridge between the capacitor and the compressor. Any issues with these components will have your compressor taking longer than usual to turn on, if ever.

Dirty Filters and Coils

Dirty air filters and coils hamper the natural airflow in air conditioning systems. The condenser coils release heat from inside your space. However, since they are in the outdoor unit, they are likely to become covered in dirt and debris, which will hamper their operation.

Similarly, your indoor air filter can become clogged by pet hair, dust, and other contaminants. In any of these scenarios, the compressor might overheat and shut down. If the compressor continues to overheat, it will break down totally.

As such, we recommend replacing your air conditioner every 45 to 90 days. Also, you should keep the area around your outdoor unit clear of branches, vines, and weeds as part of regular maintenance. 

Circuit Breaker Tripping

Your compressor won’t work if you have a tripped circuit breaker. Circuit breakers trip when you have too many appliances working at the same time.

Flipping the breaker switch back to the “on” position should solve the problem. If the breaker trips again shortly after, turn off the power supply and call a technician.

Refrigerant Problems

Air conditioners won’t cool any space without the perfect level of the right refrigerant. Overfilling the unit or using the wrong refrigerant can damage the compressor. Similarly, the air conditioner won’t work properly if there’s a leak in the refrigerant line.

If you suspect refrigerant issues, you need to call a licensed technician right away. It’s illegal to handle refrigerant if you’re not licensed for the job.

System Old Age

An air conditioner that’s older than a decade is close to the end of its lifecycle. So it’s likely that the compressor is dead and can’t be revived. If the signs point to a dead compressor, you’ll have to budget for a replacement.

Can you repair a dead compressor? No, you can only repair a damaged compressor in cases where the damage hasn’t affected the core system. Once the compressor has suffered moderate to severe damage, it’s more cost-effective to go for compressor replacement.

Keep in mind that it’s dangerous to attempt to replace the compressor on your own because it carries a high voltage. Poor handling can cause serious injury or death, so it’s best to hand over the replacement (or repairs) to a qualified HVAC technician.

Resolve Your AC Compressor Issues Today

If you’re asking, “Why won’t my AC compressor turn on?” call our team for help. We commit to resolving all HVAC problems in the most cost-effective way possible.

We’ll review your compressor and tell you the best approach to take with it. We’ll also tell you all you need to do to avoid further problems.

Call the JC Heating & Cooling, Inc. team in Hodgkins, IL, today at 708-968-3131 to book an appointment. We can take care of everything from a dead compressor to an air conditioner blowing fuses.